He admitted he had been 'veering like a shopping trolley' over decision

BoJo says he cannot turn down this 'once in a lifetime' chance to quit EU

It came just hours after PM pleaded with him live on TV to join In camp

Boris Johnson last night declared he will campaign for Britain toleave the EU because it would save money and regain control for the British people.

The Mayor of London electrified the EU referendum campaign today by ending months of speculation and dismissing David Cameron's EU deal as insignificant, saying he could not turn down this 'once in a lifetime' chance to quit the EU.

And he told the Prime Minister he was making the announcement by text just nine minutes before he appeared on live TV outside his north London home.

Mr Cameron was said to be 'absolutely furious' with the Mayor of London's decision and earlier today he made a last ditch attempt to persuade him to join the In campaign by warning against 'linking arms with Nigel Farage and George Galloway'.

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The Mayor of London, pictured outside his London home this afternoon, electrified the EU referendum campaign by announcing he was backing Brexit

Boris Johnson, pictured announcing his decision to back Brexit outside his London home, said he could not turn down the 'once in a lifetime' chance to quit the EU

Boris Johnson (right) informed David Cameron (left) that he was making the announcement by text just nine minutes before

Mr Johnson's announcement came on a dramatic day in UK politics as:

David Cameron turned on his Cabinet Brexit rebels by claiming the UK would not be able to control immigration even if it left the EU

He accused Brexit campaigners of making 'no effort' to plan for a post EU Britain

But Cabinet Eurosceptics hit back, with Chris Grayling claiming Mr Cameron's own plan would do nothing to stop Britain's population soaring to 80million

Nigel Farage dismisses Mr Cameron's claims as 'completely and utterly untrue'

Iain Duncan Smith warns staying in the EU makes Paris-style terror attacks more likely

Nicola Sturgeon warns an Out vote would lead to another Scottish independence vote

Lord Heseltine launched a scathing attack on Boris Johnson's 'illogical' decision Six Cabinet members and 15 other ministers have committed to the Out campaign

Lord Heseltine launched a scathing attack on Boris Johnson's 'illogical' decision

Six Cabinet members and 15 other ministers have committed to the Out campaign

But Business Secretary Sajid Javid helps PM by committing to In vote, along with Theresa May, Philip Hammond and Michael Fallon and others

Mr Johnson's decision hands the Out campaign a major boost but it is a big gamble for the London Mayor, who was being lined up for a major Cabinet position following the referendum.

EUROPEAN COURTS COULD CHUCK OUT DAVID CAMERON'S EU DEAL David Cameron, pictured leaving the BBC after an interview this morning, was warned that his EU deal could be challenged by EU judges A crackdown on migrant benefits promised as part of David Cameron's renegotiation deal faces being thrown out by EU courts, officials in Brussels have admitted. EU leaders have agreed to give Britain an 'emergency brake' to restrict payments of in-work benefits, such as tax credits, to migrants for their first four years in the country. But minutes after the agreement was signed on Friday, one of the EU's top negotiators said he was 'confident' it would face legal challenge – in an apparent boast that what Mr Cameron had been given could be ripped up. Legal experts yesterday warned the move to cut benefit payments to migrant workers could be overturned in the European Court of Justice. Steve Peers, professor of EU law at the University of Essex, said there are 'serious problems' with the emergency brake as European judges could rule it limits free movement rights. He said it was 'probably a long shot' that the court in Luxembourg would 'accept that these plans do not violate the (EU) Treaties'. During the marathon renegotiation discussions in Brussels on Thursday and Friday, a senior EU official also raised concerns that the brake – which Britain will be allowed to use for seven years – would be impossible to 'defend in the courts'. Mr Cameron yesterday appeared to admit it will be at least six months after the referendum that the brake will come into force – paving the way for a rush of migrants before it is introduced. The vote will take place on 23 June, but yesterday in an interview Mr Cameron suggested the brake would not be in place until next year. Some have predicted it could take even longer for the legislation needed to be passed by the European Parliament. Speaking on the BBC's Andrew Marr Show, Mr Cameron said: 'This mechanism is going to be in place for seven years. So let's say we get it in place in 2017, it will still be operating in 2024.' Advertisement

Mr Cameron, hoping to seize the initiative as the EU referendum started in earnest today, accused his own pro-Brexit Cabinet rebels this morning of misleading the public over their claims that leaving the EU would cut immigration.

He went on the offensive, declaring war on his Tory colleagues by claiming Out campaigners had made 'no effort' to plan for a post-EU Britain.

The PM, who yesterday called the historic referendum for June 23, told the Andrew Marr Show this morning that if voters decide to leave the Europe, Britain would be forced to continue to allow the EU's core principle of freedom of movement if it wanted to remain part of the single market.

But his claims were dismissed by Nigel Farage as 'completely and utterly untrue' and his own Cabinet minister Chris Grayling this morning said it was Mr Cameron's own EU plans that would see Britain's population soar to 80million.

Mr Cameron suffered another setback this afternoon as his Work and Pensions Secretary Iain Duncan Smith claimed that staying in the EU would make a Paris-style terror attack more likely to happen on UK soil.

It was a direct contradiction of the Prime Minister, who had earlier insisted that EU membership was essential in making Britain 'safer and stronger'. He mentioned the slogan nine times in his Andrew Marr interview.

But it was Mr Johnson's remarks that will hurt Mr Cameron the most.

Mr Johnson said: 'I don't think that anyone could realistically claim that this is fundamental reform of the EU or of Britain's relationship with the EU.'

Explaining that his decision was mainly based on the growing supremacy of the EU over British law, the London Mayor added: 'Sovereignty: this is not something that is possessed by politicians. 'Sovereignty is people's ability to control their lives and make sure the people they elect can pass the laws which matter to them.

'There is a problem with Europe and you are seeing this more and more with employment over border controls, over human rights, over all sorts of stuff.

'We have got a supreme judicial body in the European Court of Justice that projects down on the 500 million a single judicial order from which there is about no recourse and no comebacks. And in my view that has been getting out of control. There is too much legislation coming from the EU.'

He said he had agonised over the decision for days and said it had given him a 'huge amount of heartache'.

'The last thing I wanted was to go against David Cameron or the Government but after a great deal of heartache I don't think there is anything else I can do,' he said.

'I will be advocating vote leave ... because I want a better deal for the people of this country to save them money and to take back control.'

Mr Johnson's dramatic announcement came just hours after Mr Cameron had pleaded with him to campaign for Britain to stay in the EU.

Speaking this morning, the Prime Minister said: 'I would say to Boris what I'd say to everybody else: We will be safer, we'll be stronger, we'll be better off inside the EU.

'I think the prospect of linking arms with Nigel Farage and George Galloway and taking a leap into the dark is the wrong step for our country and if Boris, if others really care about being able to get things done in our world, then the EU is one of the ways in which we get them done.'

He added: 'We're members of Nato, we're members of the UN, we're members of the IMF, I care about Britain being able to fix stuff – whether it's stopping pirates off the African coast, whether it's closing down illegal migration routes, closing down smugglers, whether it's standing up to Vladimir Putin with sanctions, whether it's the sanctions we put in place to get Iran to abandon its nuclear plan – having that seat in the EU, just as being a member of Nato is a vital way that we project our values, our power and our influence in the world.'

Mr Johnson, pictured speaking outside his home in Islington last night, said that he had decided to back Britain leaving the EU because the European 'political project' was 'in danger of getting out of proper democratic control'

Boris Johnson (pictured outside Islington home this afternoon, right) held a secret meeting with Michael Gove (pictured left outside his home today) before deciding which side of the EU referendum campaign to join

Brexit campaigners will now attempt to persuade him to lead the Leave campaign.

Vote Leave campaigners deliver an umbrella and hat to Boris Johnson's home in Islington this afternoon after news that he will campaign to leave the EU

His decision could have a major impact on the outcome of the referendum.

A poll last week found that one in three people viewed his decision as 'important' in helping them decide which way to vote in the referendum - making his voice the second most influential politician after Mr Cameron.

His decision comes despite Mr Cameron using a live TV interview to warn him against 'linking arms with Nigel Farage and George Galloway and taking a leap into the dark'.

A Conservative party source told the Sunday Times that Mr Cameron was 'absolutely furious with Boris'.

'He has had all the perks, visits to Downing Street and he still won't commit.'

Sources close to the Mayor of London revealed that he had admitted to 'veering like a shopping trolley' over which side of the referendum campaign to join.

His sister, Rachel Johnson, this morning rejected accusations that voting for Brexit would be a 'betraying' Londoners, insisting his decision was 'enormously difficult' and predicted his announcement would have a 'very significant' on the referendum result.

'This is an enormously complicated decision for everybody… his participation in either camp is going to be very significant and this this is why he's taking so long to decide,' she told Sky News.

Mr Johnson was helped by the man hoping to succeed him as Mayor of London - the Tory candidate Zac Goldsmith, who last night said he was backing the Brexit campaign.

The Mayor of London left his south Oxfordshire home early this afternoon - shortly after David Cameron had warned him not to 'link arms with Nigel Farage and George Galloway' by joining the Out campaign

'Greater London isn't a minor appendage to the EU,' he said. 'It is a global city, with global reach. 'We dominate in financial services, tech, media, culture and much more besides. London will flourish whatever the outcome of the referendum.'

Meanwhile, Mr Duncan Smith rejected claims made by pro-EU campaigners - including Mr Cameron - that EU membership boosted Britain's national security, saying the bloc's open borders posed a threat to the UK's defence against terrorism.

'This open border does not allow us to check and control people that may come and spend time,' he told the BBC today.

'We've seen what happened in Paris where they spent ages planning and plotting so who's to say it's not beyond the wit of man that those might already be thinking about that.'

Ukip leader Nigel reacted with delight to news that Boris Johnson will be campaigning on the same side as him

But Lib Dem leader Tim Farron claimed not to be bothered by news of the London Mayor's decision

Asked by the BBC whether staying in the EU made the UK more susceptible to Paris-style attacks, he replied: 'I think the present status of the open border we have right now many of us feel does actually leave that door open and we need to see that resolved.'

BORIS JOINS GANG OF SIX CABINET REBELS TO BACK BREXIT John Whittingdale, Theresa Villiers, Michael Gove, Chris Grayling, Iain Duncan Smith and Priti Patel (left to right) attend the launch of the Vote Leave campaign yesterday By dramatically backing Brexit, Boris Johnson has joined six Cabinet rebels, who yesterday rushed to a Vote Leave rally as soon as David Cameron's historic Saturday Cabinet was over. They slipped out of the back entrance of Downing Street and headed to the headquarters of the Vote Leave group, based in a tower block on the south bank of the Thames. Michael Gove was the most prominent of the six and posed with his fellow 'freedom fighters' – as they have been dubbed by admirers – as they clutched a signed campaign banner. They are: 1) JOHN WHITTINGDALE The Culture Secretary is the last authentic Thatcherite in the Cabinet: in the 1980s he worked as her private secretary and has remained loyal to her ideology – including her Euroscepticism – since. An unlikely-seeming Meatloaf fan, Whittingdale was a tenacious chairman of the Commons Media Committee, where he subjected figures such as Rupert Murdoch to forensic interrogation. He is said to be thoroughly enjoying his portfolio, which includes a root-and-branch review of the BBC's funding. 2) THERESA VILLIERS The Northern Ireland Secretary is a Major's daughter who is descended from Edward I. Along with Chris Grayling, the Commons Leader, she is understood to have spent the past six months agonising over whether to leave the Cabinet to campaign for an 'Out' vote. However, after a chat with Mr Cameron before Christmas, she was reassured she would be allowed to campaign from within the Cabinet – sparing the PM an awkward reshuffle. Her stance has caused controversy in Northern Ireland, with local politicians claiming an EU exit could stoke sectarian tensions. 3) MICHAEL GOVE The Justice Secretary is the star name out of the six – and the one with the closest personal relationship to the Prime Minister. An ex-Times newspaper executive and author, who has been friends with Mr Cameron for more than a decade, he was part of the 'kitchen cabinet' who encouraged him to run for the Tory leadership. Throughout his Cabinet career, Gove has been Mr Cameron's first choice to help him prepare for the weekly ordeal of PMQs, amusing No 10 staffers with his razor-sharp rejoinders in practice sessions. Gove was a controversial reforming Education Secretary until moved to the Whips' Office after private party polling suggested he was an electoral liability. The move caused a 'wobble' in his and Mr Cameron's friendship. 4) CHRIS GRAYLING Mr Gove's predecessor as Justice Secretary, Chris Grayling is a long-term Eurosceptic. The Manchester United fanatic was deployed by the Tories as an energetic 'attack dog' during their long period in Opposition, harrying Labour – including the Blairs – over their personal business affairs. The 6ft 5in Leader of the House has a cool relationship with Gove, who has reversed many of his justice reforms. 5) IAIN DUNCAN SMITH Few people were surprised by Iain Duncan Smith's decision to back the Out campaign: the Work and Pensions Secretary has been a long-standing critic of the EU and supporter of tighter immigration controls. The former Scots Guards officer's undistinguished period as Tory leader between 2001 and 2003 is remembered largely for the conference speech he gave in which he portrayed himself as 'a quiet man' who was 'turning up the volume'. Duncan Smith has since rebuilt his reputation by becoming a crusading campaigner for social reform, which prompted David Cameron to put him in charge of the Government's welfare shake-up. 6) PRITI PATEL Priti Patel, who answers to Mr Duncan Smith as Employment Minister, is regarded by the former Tory leader's team as the up-and-coming poster girl for Cabinet Eurosceptics. As the daughter of Ugandan immigrants who came to this country in the 1970s to seek sanctuary from Idi Amin, she says that the welcome they received here has instilled in her a fierce British patriotism. Patel, whose political heroine is Margaret Thatcher, started out in her Westminster career working for Sir James Goldsmith's Eurosceptic Referendum Party in the 1990s, and sees her current stance as being consistent with her long-term political beliefs. Advertisement

Mr Cameron faces warnings and challenges from all sides. Nicola Sturgeon, Scotland's First Minister, said a vote to leave the EU would 'almost certainly' lead to a second referendum on Scottish independence.

'I think that would be the demand of the people of Scotland,' Ms Sturgeon told the Andrew Marr Show.

'If a couple of years later we find ourselves, having voted to stay in the European Union, being taken out against our will, I do think there are many people – including people who voted No in 2014 – who would say 'the only way to guarantee our EU membership is to be independent and that, I think, is inescapable.'

The Labour party branded Mr Johnson's decision to back the Out campaign as a play for the Tory leadership.

Shadow Europe minister Pat Glass said: 'This announcement says more about the Tory leadership contest and Boris' own positioning than what is in the best interests of Britain.

'While the successors to David Cameron are positioning themselves, Labour will focus on what's best for Britain - defending the jobs and rights protected by our EU membership.'

The Lib Dems also hit out at his decision to back Brexit, but unsurprisingly Mr Farage reacted with delight and fully endorsed the London Mayor playing a big role in the campaign.

Mr Farage tweeted: 'Delighted that Boris Johnson supports Leave side and I hope he throws his full weight behind campaign to get UK out of the EU.

Meanwhile John Mills, a Labour donor who is funding the Out campaign, hailed Mr Johnson's endorsement and described him as 'a very charismatic figure who touches people in all sorts of places'.

But former Tory deputy prime minister Lord Heseltine described his decision as 'illogical'.

'If it takes you this long to make up your mind about something so fundamental and you still have questions, then surely the right option is to stay with what you know rather than risk our economy and security with a leap in the dark,' he said.

'If he were to be successful in his ambition to cut us off from Europe, the flags would fly in Frankfurt and Paris in his honour. At a stroke, he would have blown away the safeguards for our financial services industry that the Prime Minister has just secured.

'That is to risk countless jobs across our country from Edinburgh in the north to Bournemouth in the south and, of course, London itself.'

Despite losing Mr Johnson to the Out camp, the Prime Minister was given a boost today as a poll for the Mail on Sunday showed the In campaign had a 15 per cent lead.

And in another victory for the Tory leader, the previously outspoken Eurosceptic Business Secretary Sajid Javid wrote in the Mail on Sunday that he will vote for Britain to stay in the EU, although he said he will be doing so 'with a heavy heart and no enthusiasm'.

He joins all but six Cabinet ministers in campaigning for Britain to remain a member of the EU.

Home Secretary Theresa May, who had been tipped as a leader of the Out campaign, said she was voting In on the grounds of national security, while Philip Hammond, the Foreign Secretary, and Michael Fallon, the Defence Secretary, also committed themselves to backing the PM, joining the most pro-EU Cabinet ministers such as Chancellor George Osborne and Transport Secretary Patrick McLoughlin.

On a bruising day for Mr Cameron, some of his strongest support came from the Labour party.

Shadow Foreign Secretary Hilary Benn attacked Mr Johnson's decision to join the Out campaign as serving his own ambitions to lead the Conservative party.

But although backing Mr Cameron's EU deal, he ruled out sharing a platform with the Prime Minister during the EU referendum campaign - learning from Labour's lessons during the Scottish independence referendum when they lost significant support among voters after Ed Miliband was seen to be siding with David Cameron.

Mr Benn told Sky News this morning: 'I said right at the beginning that I'm not going to be sharing any platforms with any Conservatives during this referendum campaign.

'That's why we set up our Labour campaign, headed by Alan Johnson, because... we want to talk to Labour supporters and persuade them this is the right thing to do in the interests of the country and themselves, their families, their jobs, their incomes that depend on being part of this single market...

'I will be saying that we should vote to stay in but I'm not proposing to share any platforms with the Prime Minister. We work out separate sides of the street in the course of the campaign...

'I'm not going to share any platforms with Conservatives because we've got our own Labour campaign and the Conservatives have got their own campaign. In the end, everybody who thinks it is in the national interest for Britain to remain in should do everything they can in their own way to encourage people to take that decision.'

On Mr Johnson, Mr Benn said: 'I'm surprised, really, because Boris Johnson in the past has written a lot about the importance of staying in the European Union and if he is actually thinking about putting his personal leadership ambitions above the national interest, I don't think it's going to do him any good.'

'I want a better deal for the people of this country, to save them money and to take back control': Boris Johnson's full statement

Boris Johnson, pictured speaking outside his north London home said he loved European 'culture and civilisation' but was opposed to the 'political project' it had become

'I can see that you are all in a great mass here. I know you were all wanting to ask my views on Europe. Let me tell you where I have to because I have made up my mind. I want to stress that this is not about whether we love Europe or not. I love Brussels, I used to live in Brussels, it's a fantastic city and a wonderful place.

'And I love European culture and civilisation. I believe it is the greatest civilisation this planet has ever produced and most of us are products of that civilisation. And it is a fantastic thing.

'But there should be no confusion between the wonders in Europe - and the holidays in Europe and the fantastic food and friendships and whatever else you get from Europe – and a political project that is basically going on for decades.

Boris Johnson, pictured outside his home, said the European Court of Justice had 'eroded' sovereignty

The London Mayor, pictured arriving at his north London home this afternoon, insisted today's decision was not a 'cynical ploy' for the Tory leadership

'That Britain has been a member of since 1975 and I now think is in real danger of getting out of proper democratic control.

'It's a view I have held for a long time and it is a view I have written a huge number of articles about.

SOUND-BITE DAVE: VOTERS WARNED FOR AVALANCHE OF KEY SLOGANS FROM PM David Cameron, pictured on the Andrew Marr Show this morning, said THE slogan 'safer, stronger, better off' nine times during his interview Voters have been warned to expect a four month campaign of soundbites as David Cameron repeatedly uses a handful of key phrases to try and convince people the country would be less safe if we left the EU. In the 48 hours after being handed his renegotiation deal in Brussels, the former PR man deployed the carefully crafted soundbites over and over again as he hit the airwaves to set out his referendum stall. During a 20-minute interview on the BBC's Andrew Marr Show today the Prime Minister three times warned that a vote to leave would be a 'leap in the dark'. Mr Cameron also used the phrase, which is expected to be a cornerstone of the In campaign that has been nicknamed 'Project Fear', in a speech in Brussels on Friday night and again the next morning in Downing Street as he announced the date of the referendum. In the three appearances, which were all televised, Mr Cameron used the slogan 'safer, stronger, better off', nine times – including twice in the address outside Number 10 that lasted only four minutes. He separately used the words 'safe' and 'safer' another eleven times. Despite failing to secure the curbs to migrant benefits promised at the election in the Tory manifesto, Mr Cameron repeated the expression 'something for nothing' six times as he attempted to sell the changes he did get that will stop newcomers being able to claim tax credits from day one. Mr Cameron also delivered the catchphrase 'the best of both worlds' six times and 'strength in numbers' three times. During the last parliament in the run up to last year's election, Mr Cameron deployed the phrase 'long-term economic plan' so many times it became a standing joke in Westminster. By repeating his referendum soundbites ad nauseum, Mr Cameron is no doubt hoping to get the messages lodged in the public's consciousness in the run up to the vote on 23 June. It is thought the short sharp messaging will have been tested in focus groups. Advertisement

'Sovereignty: this is not something that is possessed by politicians. Sovereignty is people's ability to control their lives and make sure the people they elect can pass the laws which matter to them.

'There is a problem with Europe and you are seeing this more and more with employment over border controls, over human rights, over all sorts of stuff.

'We have got a supreme judicial body in the European Court of Justice that projects down on the 500 million a single judicial order from which there is about no recourse and no comebacks. And in my view that has been getting out of control. There is too much legislation coming from the EU.

'I look at what the Prime Minister achieved from the EU the other day and I think given the time he had he did fantastically well. I think everyone should pay tribute to David Cameron for what he pulled off in a very short space of time. But I don't think anyone could realistically claim that this is fundamental reform of the EU or of Britain's relationship with the EU.

'And it's it's my view that after 30 years of writing about this we have got a chance to actually do something.

I would like to see a relationship based more on trade but with much less of this surpa-national element so that's where I'm coming from.

'So that's why I have decided after a huge amount of heartache because I did not want to do anything to go against David Cameron or the government but after a great deal of heart ache I don't think there's anything else I can do.

'I will be advocating Vote Leave or whatever the team is called.

'And I understand there are many of them. Because I want a better deal for the people of this country, to save them money and to take back control. I think this is what this is all about.

'I stress what I won't do is to take part in lots of blooming TV debates against other member of my party.

'And I was told about what the Prime Minister said this morning about not sharing platforms with George Galloway and other individuals – I won't do that either.

'If I'm asked my views I will give my views.'

'It has been agonisingly difficult and I think for many of us what I said over a couple of years is that I would like to be in a reformed EU. I don't think that has really been offered.'

Asked whether it was a cynical play for the Tory leadership, Mr Johnson said: 'On the contrary… I think really and truly it would be the best thing possible for the people listening to this debate who are wondering genuinely in their mind which way to go, it's so important to focus on the question in hand, it is better for Britain to remain in the EU as it currently is or is it possible to get a better deal for Britain that is did more for British democracy and restored some control to the people of this country. That's the critical thing.'

'It's not and I want to make one thing absolutely clear – whatever Whatever happens at the end of this - and I have said this to the prime minister - he [Cameron] has got to stay.

'I happen to think that I'm right. It's an awful difficult cause to make and I have thought about it for many many years. I don't see how having worried about this issue for quite so long I can then pass up what may be the only chance any of us ha in our lifetime.'

NOW YOU DECIDE: YOUR AT A GLANCE GUIDE TO HOW JUNE 23 REFERENDUM WILL WORK David Cameron, pictured on the Andrew Marr Show this morning, said holding the EU referendum was an act of sovereignty in itself as he hailed his EU deal reached with European leaders late on Friday evening With the opinion polls see-sawing – and up to 40 per cent of voters saying they could change their mind between now and June 23 – the EU referendum is up for grabs. Harold Macmillan famously declared that 'events, dear boy, events' were the biggest threat to a leader's plans. Now, another Conservative Prime Minister will be hoping the historic vote is not decided by factors beyond Downing Street's control... MIGRATION Last summer's migrant crisis, which saw hundreds of thousands of Syrians and North Africans making the perilous journey by boat to Europe, triggered a boost in the polls for the Out camp. Reports that the same migrants were responsible for sex attacks in Germany, while others were living in the 'Jungle' camp at Calais, increased the impact. Last year, an astonishing 1.83 million people illegally entered the EU, over six times as many as the previous year. This is why Downing Street was so keen to hold the referendum in June. The next possible date was after the summer, by which time the migrant situation could have deteriorated even further. This year's crisis is predicted to be even more serious than last year. If so, it could hand victory to the 'Out' campaign. JOBS David Cameron needs Chancellor George Osborne – who is also the Government supremo trying to engineer a win for the 'In' campaigners – to deliver a feelgood Budget in May. If voters are positive about their personal financial circumstances, they are less likely to vote for change. More important will be the performance of the wider EU economy. A repeat of the eurozone crisis of two years ago, when Greece and other southern European governments were on the brink of collapse, would reinforce the notion that Britain's economy would thrive outside the bloc – and with it a burst of job creation. 'In' campaigners will insist that British jobs are heavily tied to our trade links with our EU partners. In a speech yesterday, Labour leader Jeremy Corbyn said: 'Being part of Europe has brought Britain investment, jobs and protection for workers.' But 'Out' campaigners will highlight sluggish growth rates across the EU as a reason to break free. SECURITY Downing Street is planning to claim that if Britain leaves the EU, we will be less protected against threats such as Putin's Russia because hostile powers are intimidated by the unity of the 28-state EU. 'Out' campaigners will counter this argument by highlighting the security risks presented by lax border controls. The terror attacks in Paris last November accentuated these fears, particularly after it was revealed that some of the perpetrators had posed as migrants to enter Europe. Home Secretary Theresa May has argued that being part of the EU is a major benefit to British security services as a result of cross-border intelligence sharing and valuable reciprocal agreements such as the European Arrest Warrant. SOVEREIGNTY Cameron has tried to win over London Mayor Boris Johnson to the 'In' campaign by promising to enshrine in British law a pledge guaranteeing the ultimate supremacy of Parliament over Brussels – and hopes voters will also be persuaded. The Prime Minister was today expected to promise to make clear that the British Supreme Court outranks the European Court of Justice, similar to an idea first put forward by Johnson last year as the price for his support for the 'In' group. He says it is critical the sovereignty of the House of Commons is 'put beyond doubt'. Legal experts say the move is pointless as Parliament already has the power to ignore EU law if it chooses to, it is just that the sheer volume of Brussels legislation makes it impractical – but it may have some impact on voters' sentiment due to the 'political theatre' it represents. INFLUENCE The Prime Minister is planning to make British influence on the world stage a key strand of his campaign – arguing that we have far more clout combined with our EU partners, rather than as a 'lone wolf'. It explains the slogan of the 'In' campaign group: 'Britain Stronger in Europe.' The arguments will be played out whenever a diplomatic crisis strikes, such as attempts to settle the war in Syria, but are likely to pivot on economic considerations. The 'In' camp says that Britain is better able to open up new trade markets by acting with other EU countries. The 'Out' camp says British businesses are dragged down by Brussels' red tape and would flourish by forging fresh alliances within the Commonwealth. They say our influence within the EU is illusory because we are routinely outvoted on important decisions in Brussels, winning only eight per cent of the votes on vital EU decisions. RISK The 'In' camp believes its trump card is 'Project Fear' – making sure voters are too frightened to make a 'leap in the dark' and instead plump for the security of the status quo. They will say we cannot risk being cut off by our EU partners. 'Out' campaigners will argue the UK is risking its future by being subservient to Brussels and make reassuring noises about life outside the EU. As leading 'Outer', Cabinet Minister Chris Grayling said yesterday: 'Does anybody actually think that on the day after Britain leaves the EU, the Germans are going to turn around and say, 'We're not going to sell you BMWs any more'? Advertisement

Michael Gove and Boris EXPOSED in secret EU plot: Pair held four hour talks at Johnson's Islington home on eve of Cabinet rebel's 'exit' as London Mayor admits he's 'veering like a trolley'

Boris Johnson had secret talks with Cabinet rebel Michael Gove last week on whether to defy David Cameron over the EU referendum, The Mail on Sunday can reveal.

The two dined at the London Mayor's home on Tuesday, where they agreed the Prime Minister's new EU deal was 'thin'.

Shortly afterwards, Justice Secretary Mr Gove shocked No 10 by joining the 'Out' campaign to cut Britain's ties with Brussels.

Left, Boris Johnson's wife, lawyer Marina Wheeler - an outspoken critic of the PM's deal - leaves the family home before Michael Gove arrives. Right, a smiling Justice Secretary emerges from Boris's front door

Left, perhaps the pair were expecting a long, sweaty discussion to rival the EU negotiations, as a courier arrives to deliver new shirts. Right, the meeting was also attended by Mr Gove's wife, Sarah Vine

The disclosure of the secret dinner – and the pair's sharp criticism of the outcome of Mr Cameron's negotiations – will fuel speculation about which side Mr Johnson will back in the forthcoming EU referendum.

He is said to have told a Westminster contact: 'I'm veering all over the place like a shopping trolley.'

According to Tim Shipman at The Sunday Times, one source close to Mr Johnson said: 'It's a very difficult call for him. He is really conflicted. I think his heart is for out, but there is an enormous amount of pressure.'

STURGEON WARNS OF SECOND SCOTTISH REFERENDUM Scotland will ‘almost certainly’ hold a second referendum on quitting the UK in the event of Brexit, SNP leader Nicola Sturgeon warned today. The first minister said if Scotland was taken out of the EU against its will, there would be an ‘inescapable’ shift in public opinion toward independence. She also claimed it was ‘inevitable’ that people who voted No in 2014 would change their minds. But Mrs Sturgeon insisted that David Cameron should stay south of the border during the EU referendum campaign in case his intervention pushed Scots toward the exit. Advertisement

Another Tory source said: 'Cameron is absolutely furious with Boris. He has had all the perks, visits to Downing Street and he still won't commit.'

Yesterday, Mr Gove and five fellow Ministers staged a dramatic revolt at a crisis Cabinet meeting on the referendum – the first time the Cabinet has assembled on a Saturday for more than half a century.

Friends of the Mayor said last night he was still 'agonising' over his stance on the issue.

He is said to be concerned that if he fails to back Mr Cameron it could hurt his chances of securing a big cabinet job, potentially as foreign secretary, after the EU referendum.

Today, Mr Johnson's sister said he was not 'milking' his decision over Britain's membership of the European Union for 'maximum publicity'.

Writer and broadcaster Rachel Johnson said her brother had to make a 'very, very hard' choice as there are good and bad arguments on both sides.

She added that Mr Johnson's presence in either the Remain or Leave campaign will be 'very significant' - which is why he is taking so long to decide.

THE MAGNIFICENT SEVEN: WHAT THE TOP TORIES BACKING BREXIT SAY ABOUT BRITAIN'S MEMBERSHIP OF THE EU By dramatically backing Brexit last night, Boris Johnson has joined six Cabinet rebels, who were finally free to speak their mind on the EU at the weekend. The - 'freedom fighters' - as they have been dubbed by admirers - are: BORIS JOHNSON The London Mayor finally came off the fence last night, ending months of speculation over which side of the referendum campaign he would join. Mr Johnson invoked the glories of the British Empire and the leadership of Winston Churchill to say the country which gave the world parliamentary democracy should not subject itself to 'legal colonisation' from the EU. 'This is a once in a lifetime chance to vote for real change in Britain's relations with Europe. This is the only opportunity we will ever have to show that we care about self-rule. 'A vote to Remain will be taken in Brussels as a green light for more federalism, and for the erosion of democracy.' MICHAEL GOVE The Justice Secretary is one of David Cameron's closest friends - he was part of the 'kitchen cabinet' who encouraged him to run for the Tory leadership - and his decision to join the Out campaign on Saturday was the first major blow for the PM. In a 1,500-word essay explaining his decision to leave the EU, which he described as 'mired in the past,' Mr Gove wrote: 'Far from providing security in an uncertain world, the EU's policies have become a source of instability and insecurity.' IAIN DUNCAN SMITH Few people were surprised by Iain Duncan Smith's decision to back the Out campaign: the Work and Pensions Secretary has been a long-standing critic of the EU and supporter of tighter immigration controls. But yesterday he directly contradicted David Cameron's claim that Britain was 'safer and stronger' in the EU by claiming staying in the EU would make Britain more vulnerable to a Paris-style terror attack. And savaging the PM's EU deal, Mr Duncan Smith wrote in today's Daily Mail: 'The truth is that there is nothing proposed in last Friday's agreement that reduces or returns the enormous powers that the Commission and the Court of Justice have over our national government.' Priti Patel The employment minister is regarded as the up-and-coming poster girl for Cabinet Eurosceptics. Her decision to join the Out camp was no surprise but her popularity with Tory grassroots will deal a blow to the PM. She has railed against the 'democratic deficit' of the EU's institutions, adding: 'My experience in business is that organisations are only successful and efficient when they are accountable and flexible – and the EU is neither.' JOHN WHITTINGDALE The Culture Secretary is the last authentic Thatcherite in the Cabinet: in the 1980s he worked as her private secretary and has remained loyal to her ideology – including her Euroscepticism – since. At the weekend he called for Britain to 'recover the powers we have lost' and said Cameron's pledge to reduce net immigration to the tens of thousands would be 'impossible' while remaining a member of the EU. CHRIS GRAYLING Mr Gove's predecessor as Justice Secretary, Chris Grayling is a long-term Eurosceptic. The Manchester United fanatic was deployed by the Tories as an energetic 'attack dog' during their long period in Opposition, harrying Labour – including the Blairs – over their personal business affairs. The 6ft 5in Leader of the House has a cool relationship with Gove, who has reversed many of his justice reforms. THERESA VILLIERS The Northern Ireland Secretary has long backed quitting the EU and made her views clear straight after Saturday's Cabinet meeting. She said she will vote to leave the EU 'to take back control over our country and making our laws and controlling our borders'. Advertisement

One in four Conservative MEPs will rebel against David Cameron and back Brexit

A quarter of Tory MEPs will defy David Cameron by campaigning for Brexit, it has been revealed.

Five of the 20 Conservatives who sit in the European Parliament have informed the Prime Minister they will vote to Leave despite his renegotiation deal. A further three are yet to make up their minds.

Ashley Fox, the leader of the Tory group in the Brussels, yesterday said Mr Cameron had made clear to MEPs there would be 'no recriminations' for their decisions.

Five of the 20 Conservatives who sit in the European Parliament have informed the Prime Minister they will vote to Leave despite his renegotiation deal

The MEP for the south west and Gibraltar said the Prime Minister had not asked for enough in his renegotiation, but said he would vote for the country to remain an EU member to ensure continued access to the single market.

During the renegotiation, Mr Fox privately urged Mr Cameron 'to go as far as he could' with his demands and wanted him to get back national control of employment regulations such as the working time directive.

But he said Mr Cameron had been hampered by the reluctance of other countries to revise the EU's founding treaties.

'I wish we had achieved more in the renegotiation. I think what the Prime Minister has achieved are useful improvements to our membership, but I would have liked to have seen more demands in the first place and a larger repatriation of powers to the UK,' he said.

'It has been a difficult decision, but we now face a binary choice, it's either in or out, so there's no point now saying 'oh, I wish this had happened'.

'I have come down on the Remain side. In my constituency I have Rolls-Royce, Honda and Airbus and it's critically important that they have full access to the single market. I believe that leaving puts that at risk.'

Mr Fox said that in meetings with MEPs, Mr Cameron had 'made clear that after the referendum the Conservative party has to come together'.

'Of course he wants his MPs and MEPs to support him, but he's also been clear there is not some dreadful threat hanging over us if we go for Leave,' he added.