Vote Leave campaigners have accused Downing Street of desperation as polls still neck and neck with 45 days to go

The Tory war over the EU escalated last night with Boris Johnson accusing David Cameron of corroding public trust in politics by failing to curb mass immigration.

On the most frenzied day of the campaign so far, the rival camps clashed over a warning from the Prime Minister that Brexit could make war in Europe more likely.

Mr Johnson said this was ‘wholly bogus’ – and claimed that far from keeping the peace, the EU had stoked tensions in Ukraine.

The Tory leadership contender also hammered Mr Cameron for his failure to get a grip on immigration – which he said was impossible while Britain was an EU member.

The Prime Minister makes his point on the EU during the keynote address in London this morning, but Boris Johnson hit back within hours

He said: ‘It is deeply corrosive of popular trust in democracy that every year UK politicians tell the public that they can cut immigration to the tens of thousands – and then find that they miss their targets by hundreds of thousands.’

Mr Johnson also said that the Russian invasion of Ukraine proves ‘the EU’s pretensions to a defence policy’ has caused ‘real trouble’. However supporters of the Remain campaign hit back at his comments – branding him a ‘Putin apologist’.

The response came after the premier used a keynote speech to deliver the most dramatic warnings so far about the consequences of leaving the EU.

Mr Cameron insisted it would be harder to keep terrorists off the streets of London if we gave up membership after the ballot on June 23, and even raised the prospect of the continent sliding back into conflict.

Flanked by Labour's former foreign secretary David Miliband in the latest example of how the battle is blurring party loyalties, Mr Cameron invoked Winston Churchill and the sacrifice of British soldiers during the Second World War.

He took a brutal swipe at his Justice Secretary Michael Gove and other Brexit campaigners for 'toying' with the livelihoods of the public by demanding we get out of the EU without any serious plan for what happens afterwards.

BOJO ON DAVE AND HOW THE PRIME MINISTER CHANGED HIS TUNE On his promise to cut migration: It is deeply corrosive of popular trust in democracy that every year politicians tell the public they can cut immigration to the tens of thousands – and then miss their targets by hundreds of thousands. On the PM’s deal with Brussels: There has been not a single change to the treaty, nothing on agriculture, nothing on the role of the court, nothing of any substance on borders – nothing remotely resembling the agenda for change that was promised in 2013. On the PM’s warning of war: It is very, very curious that the Prime Minister is warning us that World War Three is about to break out unless we vote to remain. I think that is not the most powerful argument I’ve heard. And what Mr Cameron thought about Brexit in February: I will never argue that Britain couldn’t survive outside the European Union… Let me say again, if we can’t secure these changes, I rule nothing out. Advertisement

But Tory MP Mr Johnson responded within hours, telling a Vote Leave event: 'I don’t think the prime minister can seriously believe that leaving the EU would trigger war on the European continent given that he was prepared only a few months ago to urge that people should vote leave if they failed to get a substantially reformed European Union.

The former London Mayor dismissed the 'peace-in-Europe' argument that the UK needed to stay in 'to prevent German tanks crossing the French border'.

Mr Johnson insisted Nato was the reason why peace had been largely preserved in Europe since the Second World War, describing the claims as 'very very curious'.

The MP, who will tomorrow launch a UK bus tour, also cited a speech given by Mr Cameron at Bloomberg in 2013.

He noted that Mr Cameron said he was willing to campaign to leave if he did not achieve real reform and treaty change, adding: ‘And that is frankly what the Government should now be doing ... There has been not a single change to EU competences, not a single change to the treaty, nothing on agriculture, nothing on the role of the court, nothing of any substance on borders’.

In other signs that the EU debate is gathering pace:

Mr Cameron cited 'newly belligerent Russia' as a reason to stay in the EU

He pleaded with voters not to make the ballot a verdict on his own future amid fears Labour activists could be swayed by trying to kick him out

Downing Street was accused of trying to scupper TV debates by refusing to allow Tories to go head-to-head

The former head of MI5 was dragged into a row over whether British citizens are safer inside the EU

Environment Secretary Liz Truss claimed 40,000 jobs in the Scottish industry would be put at risk

At one point Mr Johnson even delivered a snatch of Beethoven's Ode to Joy as he dismissed accusations that Leave campaigners are 'Little Englanders'.

'I find if offensive, insulting, irrelevant and positively cretinous to be told – sometimes by people who can barely speak a foreign language – that I belong to a group of small-minded xenophobes,' he said. 'Because the truth is it is Brexit that is now the great project of European liberalism, and I am afraid that it is the EU – for all the high ideals with which it began, that now represents the ancien regime.'

Downing Street later admitted that despite the dire warnings about war, no government officials are currently making contingency plans.

'The Government has a position that we should vote to remain and we are not contingency planning for leaving,' a spokesman for the Prime Minister said.

One of Mr Cameron's most shocking claims was about the impact on the UK's ability to tackle Isis outside the EU.

'It takes a network to defeat a network and European measures are a key weapon,' he said.

'I don't argue that if we left we would lose any ability to co-operate with our neighbours on a bilateral basis, or even potentially through some EU mechanisms.

'But it's clear that leaving the EU would make co-operation more legally complex and make our access to vital information much slower and more difficult.'

Mr Cameron said warnings by two former spy chiefs - Lord Evans of Weardale, former director-general of MI5, and ex-MI6 chief Sir John Sawers - that Brexit could harm the country's ability to fight terrorism were 'unmistakable'.

The Paris and Brussels attacks were a reminder that 'we face this threat together and will only succeed in overcoming it by working much more closely together'.

David Cameron delivers his speech on the EU referendum at the British Museum in central London this morning

He said the rise of a 'newly belligerent' Russia, the fight against Isis, and the migration crisis required 'unity of purpose'.

He conceded that the Nato alliance was the 'cornerstone' of national defence - but argued that 'top military opinion' was clear that the EU is a 'vital' reinforcement to the organisation.

Mr Cameron attacked those who want the EU to collapse and claimed if Britain triggered such a move it would be an 'act of supreme irresponsibility'.

'Now is a time for strength in numbers. Now is the worst possible time for Britain to put that at risk. Only our adversaries will benefit.'

There was also controversy last night over Mr Cameron’s speech being declared a Government event. Britain Stronger In Europe helped to publicise the talk, but by stating it was arranged by the Cabinet Office it does not count towards official referendum spending limits.

Despite Mr Cameron’s doom-laden warnings that Brexit could lead to war, a No 10 spokesman said: ‘We are not doing any contingency planning because we have a policy position that we should remain within the EU.’

They also slapped down Mr Johnson’s comments on Ukraine, saying: ‘The illegal annexation of Crimea was brought about by Russia alone, and the EU sanctions are having a positive effect.’

POLITICAL CROSS-DRESSING AS DAVID MILIBAND INTRODUCES CAMERON AT PRO-EU SPEECH The former Labour foreign secretary David Miliband (pictured introducing David Cameron this morning) jetted across the Atlantic to help out the Prime Minister's bid to keep Britain in the EU Labour leader Jeremy Corbyn has refused to share a platform with David Cameron during the EU campaign but that didn’t stop David Miliband – the man who wanted both their jobs – jetting across the Atlantic to help out the Prime Minister this morning. The former Labour foreign secretary said he was fully aware that many will ‘poke fun at our unusual and temporary alliance’ as he introduced the Prime Minister ahead of his key EU speech at the British Museum. But he said it was a ‘mark of the stakes’ that they had come together and their partnership was a ‘sober reflection’ of how serious the threat of Brexit posed. Mr Miliband fled to the United States after losing out to his brother Ed in the 2010 Labour leadership election and now pockets £400,000-a-year in charge of the International Rescue Committee in New York. Defending the show of political cross-dressing this morning, Mr Miliband said: ‘There is a centre-left case for Britain's membership of the EU. 'There is a centre-right case for Britain's membership. ‘Together they add up to a compelling national case, and they need to be brought together in a way that is positive, patriotic and effective.’ He went on to warn that quitting the EU would be ‘political suicide’ and would be the ‘greatest voluntary redundancy of political power’ by any country in modern times. Joking about the likely ridicule the picture of him and Mr Miliband would generate, Mr Cameron joked: ‘I look forward to the Private Eye cover with trepidation’. To hammer home the cross-party message of the event this morning, the In campaign wheeled out another former foreign secretary, Jack Straw, as well as a host of Tory MPs, ministers, who sat alongside an audience of foreign ambassadors in the lobby of the British Museum in central London. Advertisement

Brexit campaigners have accused Downing Street panicking with the polls neck and neck despite the intervention of Barack Obama and a series of dire warnings about the risks of leaving.

Chancellor George Osborne warned yesterday that house prices could collapse following a vote to quit the union.

In his speech, described as his biggest of the campaign so far with just 45 days until the nation goes to the polls, Mr Cameron said he thought of the sacrifice of British forces during the war whenever he went to EU summits.

He said Churchill had 'never wanted' the UK to be alone and 'argued passionately' after the Second World for Europe to cooperate more closely.

'Isolationism has never served this country well,' Mr Cameron said. 'Whenever we turn our back on Europe, sooner or later we come to regret it. We have always had to go back in, and always at much higher cost.'

'Can we be so sure that peace and stability on our continent are assured beyond any shadow of doubt?

'Is that a risk worth taking? I would never be so rash as to make that assumption. It's barely been 20 years since war in the Balkans and genocide in Srebrenica.

He claimed that 'the serried rows of white headstones in lovingly tended Commonwealth war cemeteries stand as silent testament to the price this country has paid to help restore peace and order in Europe'.

'In the last few years, we have seen tanks rolling into Georgia and Ukraine. And of this I am completely sure. The European Union has helped reconcile countries which were at each others' throats for decades.

'Britain has a fundamental national interest in maintaining common purpose in Europe to avoid future conflict between European countries. And that requires British leadership, and for Britain to remain a member.'

Mr Cameron also cited the threats to Britain from the Spanish Armada and in the Napoleonic Wars.

'We know that to be a global power and a European power are not mutually exclusive. And the moments of which we are rightly most proud in our national story include pivotal moments in European history – Blenheim, Trafalgar, Waterloo,' he said.

'Our country's heroism in the Great War. And most of all our lone stand in 1940, when Britain stood as a bulwark against a new dark age of tyranny and oppression.

'But it wasn't through choice that we were alone.

'Churchill never wanted that. He spent the months before the Battle of Britain began trying to keep our French allies in the war, and then after France fell, he spent the next 18 months persuading the United States to come to our aid.

'And in the post-war period he argued passionately for Western Europe to come together, to promote free trade, and to build institutions which would endure so that our continent would never again see such bloodshed.

'The truth is this: what happens in our neighbourhood matters to Britain. Either we influence Europe, or it influences us.

'And if things go wrong in Europe, let's not pretend we can be immune from the consequences.'

Former London Mayor Mr Johnson said the claims by the Prime Minister were 'very curious'

Mr Cameron built on warnings from security experts yesterday to claim Brexit would make Britain more vulnerable to terrorists.

He even cited 'newly belligerent Russia' as a reason we need to stay in the EU as well as the threat of ISIS and the instability caused by the migration crisis hat has engulfed Europe.

THE QUESTIONS HE'LL ASK THE PM How can you possibly control immigration into this country when you are bound by rules on free movement? How will you ensure the national living wage will not act as a pull to more migrants? How can we stop the European Court of Justice from interfering on immigration, human rights and asylum – most of which have nothing to do with the single market? Why did the Government give up the UK veto on further moves towards fiscal and political union? How can Britain stop itself from being dragged into an ever-closer union and picking up the bill for bailouts of struggling members? Advertisement

He said UK authorities' access to vital intelligence on jihadists would be 'much slower and more difficult' outside the EU.

'When people are trying to kill and maim people on British streets, the closest possible security cooperation is far more important than sovereignty in its purest theoretical form,' he said.

Mr Cameron warned that the security threat had grown since he entered Downing Street in 2010, adding: 'The threat level is now at severe, which means a terror attack is highly likely. Indeed, such an attack could happen at any time.'

Asked what his priorities will be when Britain takes over the rotating presidency of the EU next year, Mr Cameron said he would seek to finalise trade deals with the likes of Japan and the US and concentrate on fighting terrorism.

Asked how he would unite the party after making such strong attacks on his Cabinet colleagues, he said: 'Well we're working in cabinet today.

'I think it is an unprecedented - unprecedented in 40 years - act to come out and allow people to campaign in a personal capacity but this issue is so big, opinions are so strongly held, I think it's he right thing to do.

'The fact is we are running a government and making decisions right now.'

Mr Cameron with Labour's former foreign secretary David Miliband after the Prime Minister delivered a pro-EU speech at the British Museum in London

Foreign Secretary Philip Hammond, a Remain supporter, was seemingly attempting to play down Mr Cameron's words on European war earlier.

'What he’s doing is pointing out that although we in Britain have enjoyed peace and stability for many, many years, not all parts of the European continent have been that fortunate,' he told BBC Radio 4's Today programme. 'Not all parts have the deep and long democratic traditions that we have and not all parts are as stable as we are. And he’s pointing out as well that the European Union is one of the institutions that ensures peace, stability and security in our continent.'

PM DODGES TV SHOWDOWN WITH BREXIT BACKER BORIS JOHNSON Downing Street has been accused of trying deliberately to scupper referendum debates on TV by refusing to involve the Prime Minister. Both the BBC and ITV want to hold major events in the days leading up to the June 23 vote featuring the biggest hitters from the In and Out campaigns. Boris Johnson and Michael Gove are lined up to lead the charge for Leave but No 10 strategists refuse to sanction so-called 'blue on blue' clashes with David Cameron. Yesterday, George Osborne refused repeatedly to say the PM would be prepared to face Mr Gove or Mr Johnson. He told ITV's Robert Peston: 'On the Leave side you've got some Conservatives and Ukip. On the remain side you've got the Conservative leadership, the Labour Party, the trade union movement, the Green Party.' Asked why they could not have a head-to-head debate, the Chancellor replied: 'I know everyone wants to turn it into a Tory soap opera but it's more important than that.' Organisers of the BBC event at Wembley Arena are said to be in negotiations for Labour leader Jeremy Corbyn to lead the In team after both Mr Cameron and Mr Osborne ruled themselves out. Advertisement

Mr Johnson, is due to embark on a nationwide bus tour starting on Wednesday, said: 'I think it is very, very curious that the prime minister is now calling this referendum and warning us that world war three is about to break out unless we vote to remain. I think that is not the most powerful argument I’ve heard.'

Warning that 'scare stories' from the Remain campaign risked damaging the UK, he said: 'The biggest single threat that I can see is that people on the Remain camp will continue to run scare stories about world war three, or bubonic plague, or whatever it happens to be, and they may in the end inadvertently do material damage to people’s confidence about this country.'

Leading historians, including the former head of history at Cambridge University, Professor David Abulafia, have dismissed the claim that the EU has brought peace to Europe as 'historically illiterate'.

They say it is Nato that has kept us safe since 1945.

It was also the Nato alliance that managed Europe's defence against the Soviet Union in the Cold War and which organised European action after 9/11, it is argued.

But to ram home the PM's point, the Britain Stronger in Europe campaign will release a video in which four war heroes will make the 'patriotic case' for the EU.

Harry Leslie Smith, David Meyland, Patrick Churchill and Field Marshal Lord Bramall will all make their arguments for staying in the EU over the 'isolationism' that would be foisted on Britain.

Lord Bramall, a former chief of the defence staff, says: 'We would be going backwards not forwards in what we set out to cure after the terrible tragedies of the Second World War.'

BORIS BRANDED 'PUTIN APOLOGIST' OVER BLAMING EU FOR UKRAINE CRISIS Boris Johnson has been accused of being an 'apologist' for Vladimir Putin after he suggested the EU was to blame for the Ukraine crisis. The former London Mayor suggested that Brussels was responsible for the face-off that saw Russia annex Crimea and fuel unrest in the rest of Ukraine. 'If you want an example of EU foreign policy making on the hoof, and the EU’s pretensions to running a defence policy that have caused real trouble, then look at what has happened in Ukraine,' Mr Johnson said at a Vote Leave event in London today. 'What worries me now is that it is the European Union’s pretensions to run a foreign policy and a defence policy that risk undermining Nato. Labour MP Chuka Umunna hit out at Mr Johnson's comments on Twitter 'We saw what happened in Bosnia. We’ve seen what happened in the Ukraine ... All the EU can do in this question is cause confusion and, as we’ve seen in the Balkans ... and in the Ukraine things went wrong as well.' But Labour's former foreign secretary Jack Straw said: 'Boris Johnson has plumbed new depths today by joining the likes of Farage, Le Pen and Wilders in blaming the EU, rather than Vladimir Putin, for what has happened in Ukraine. 'If further evidence were needed about the careless disregard for our security demonstrated by Leave campaigners, by being a Putin apologist, Johnson has provided it.' Labour MP Chuka Umunna posted on Twitter: 'So Pres Putin annexes Crimea,which is recognised by the world to be part of Ukraine, and Boris suggests that's the EU's fault. Extraordinary.' Advertisement

Lone stand: David Cameron said that Britain stood as a bulwark against a new dark age of tyranny and oppression in 1940. Pictured, Hitler's SA officers on an exercise outside Munich

Brexit will aid enemies, say Nato chiefs

Backing Cameron: Lord Carrington, pictured, was one of five Nato chiefs who signed an open letter

Five former Nato secretaries-general last night backed the Prime Minister's stance that Britain being in the EU makes Europe safer.

An open letter published in The Daily Telegraph was signed by Lord Carrington, Javier Solana, Lord Robertson, Jaap de Hoop Scheffer and Anders Fogh Rasmussen.

They said the European Union was a 'key partner' for Nato and helped to 'stave off instability' on the continent and wider region.

'At a time of global instability, and when Nato is trying to reinforce its role in Eastern Europe, it would be very troubling if the UK ended its membership of the EU.

'While the decision is one for the British people, Brexit would undoubtedly lead to a loss of British influence, undermine Nato and give succour to the West's enemies.'

In a letter to The Times, 13 former US secretaries of state and defence, and security advisers, also warned Brexit would 'diminish' Britain's 'place and influence' in the world and leave Europe 'dangerously weakened'. Signatories included former defence secretary Leon Panetta and former secretaries of state Madeleine Albright and George Shultz.

But in an excoriating attack, war heroes who served in Bomber Command accused David Cameron of 'insulting the dead' and said the freedom they fought for was being 'eroded' by the EU. They said an 'unelected body that imposed control' was not what they had risked their lives for when they went into battle against the Nazis in 1939.

The dramatic interventions came after Mr Cameron warned that Europe risked sliding back into war if Britain voted to leave the EU. He evoked Winston Churchill, the Second World War and the graves of the fallen and said 'isolationism has never served this country well'.

But Wing Commander John Bell, 93, who served in the 617 'Dambusters' squadron, said Mr Cameron's comments were 'disgusting'.

Taking a stand: Former Nato secretaries-general Jaap de Hoop Scheffer, left, and Lord Robertson, right

He added: 'We fought for freedom during World War Two and the EU has eroded our freedom. The EU is an unelected body that imposes control on its member states and this was not the freedom that we fought for.'

David Fellowes, 92, who also served in Bomber Command, said: 'I've got one word – tripe. Mr Cameron's comments were complete and utter nonsense. Myself and others fought a war between 1939 and 1945 to save Europe from being run under the Nazis.

'We fought for our freedom, our independence, and we lost a lot of men and now he (Mr Cameron) wants to throw it all away.'

Better together: Javier Solana, left, Anders Fogh Rasmussen, right, both spoke out against Brexit

Colonel Richard Kemp, an Afghanistan veteran, said: 'I believe that if we stay in, we will be part of an EU army. An EU army would undermine deterrence and cripple Nato, weakening European defences when we face increasing threats from Russia, Middle East and radical Islam.'

Joe Lancaster, 97, who served in Bomber Command, added: 'David Cameron is away with the fairies. The EU is one great gravy train. We didn't fight for the European Union, it is no good. I don't see any logic in what Mr Cameron says.' Mr Lancaster, who is helping to build a Bomber Command education centre in Lincolnshire, added: 'It is not the EU that has stopped us going to war again.'

Mike Brundle, who served in the RAF for more than 25 years, and whose father Bert served in Bomber Command, said Mr Cameron's comments were 'an insult to those who lost their lives'.

Don't make this referendum about me, pleads Cameron

David Cameron delivers his pro-EU speech today

David Cameron insisted the battle over Britain's EU membership is 'bigger than any politician' today amid fears voters could use the referendum as an opportunity to kick him out.

The Prime Minister said told the audience at the British Museum in central London that he understood why many people - including some in his own Cabinet - were 'wrestling' with the decision.

But he insisted that the UK would suffer an 'immediate economic shock' and be 'permanently poorer' afterwards.

The ballot on June 23 was not just an ordinary election like last week's for councils and devolved assemblies, the premier argued.

'In 45 days' time, British people will go to polling stations across our islands and cast their ballots in the way we've done in this country for generations,' he said.

'They will as usual weigh up the arguments, reflect on them quietly, discuss them with friends and family and then calmly, without fuss take their decision.

'But this time their decision will not be for a parliament or even two; they will decide the destiny of our country – not for five years or for ten – but in all probability for decades, perhaps a lifetime. This is a decision that is bigger than any individual politician or government.

'It will have real, permanent and direct consequences for this country and every person living in it. Should we continue to forge our future as a proud, independent nation while remaining a member of the European Union as we have for the last 43 years or should we abandon it?'

Mr Cameron warned that it would have a major impact on the future of the country that would last for generations to come.

Mr Cameron has repeatedly denied that he will quit if the UK votes to leave the EU against his advice.

But Tory big beasts including Europhile Ken Clarke have made clear the PM could not last 'five minutes' after a Brexit vote.

The Remain camp is concerned that Labour voters, generally thought to be more in favour of staying in, may be swayed by the prospect of evicting Mr Cameron from Downing Street.

PM's brutal slapdown to Justice Secretary Michael Gove for 'toying with livelihoods'

David Cameron has launched a blistering attack on his close friend Michael Gove after he said yesterday that a Brexit vote would mean leaving the single market.

The Prime Minister said it was 'reckless' and 'irresponsible' to suggest the UK would be better off outside the market and in a remarkable broadside on his Justice Secretary, he added: 'These are people's livelihoods being toyed with.'

Mr Cameron also claimed that if Boris Johnson and Mr Gove lead us out of the EU it would be an 'abject act of retreat' for the first time in our country's history.

Asked why he called the referendum if he believed it risked causing another world war, Mr Cameron said: 'You shouldn't hold an independent and sovereign nation in an organisation against its will and this is a great act of national sovereignty.'

'The EU is one of the institutions that has helped bring peace to our continent... There is no doubt the EU has helped.'