Tory Eurosceptic MPs today rounded on David Cameron's plans to reform the European Union, dismissing his list of demands as 'thin gruel' which would fail to impress the British people.

The Prime Minister claimed his shopping list of changes including protection for Britain from a 'United States of Europe' and a block on Brussels diktats was a 'big task' but not 'Mission Impossible'.

But he was accused of being in retreat on a pledge to get a deal on banning benefits for migrants for four years, as he admitted he was 'open to different ways of dealing with this issue'.

The European Commission said the plan amounted to 'direct discrimination between EU citizens' and was 'highly problematic'.

London Mayor Boris Johnson warned there will be 'blood on the carpet' in Brussels as Mr Cameron pushes for change.

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The Prime Minister used a speech in London to warn that the answer to every problem is 'not always more Europe', as he called for curbs on benefits, limits to Brussels diktats and protection from bailing out the eurozone

Tory MPs including Jacob Rees-Mogg, Sir William Cash and Bernard Jenkin dismissed Mr Cameron's demands as 'thin gruel' which will leave voters asking: 'Is that it?'

Mr Cameron insisted major changes were need as the price for keeping Britain in the EU, and warned his planned referendum could not be reversed, adding: 'Leave means leave.'

He demanded Brussels rules be rewritten to protect Britain from becoming 'tangled' in a United States of Europe ensure non-euro countries are not forced to bail out the single currency.

If he gets what wants he will campaign 'with all my heart and all my soul' for Britain to stay in the EU in his promised referendum but if they refuse to meet his demands, he will 'rule nothing out'.

He claimed that clawing back powers from Brussels is not 'Mission Impossible' as he ended months of speculation by finally publishing a letter setting out his price for keeping Britain in the EU.

His four key demands are:

Ban on EU migrants claiming benefits for four years as part of tackling 'abuses of the right to free movement'

Legal protection for Britain and the other eight EU countries which do not use the euro from problems with the single currency

Cut the total burden on business and drive up competitiveness

An end to the concept of 'ever closer union' and a veto for national governments to block Brussels laws

But critics accused him of demanding several things which the EU was already committed to, and not addressing the big issues which concern voters including controlling the number of people who can come to Britain.

In the Commons Tory MP Jacob Rees-Mogg told Europe Minister David Lidington: 'You must know that this is pretty thin gruel - much less than people had come to expect from the Government.

'It fails to restore control of our borders.'

Sir William Cash dismissed the negotiation plan as a 'pig in a poke'. He added: 'Teaty change is needed for virtually every proposal. Treaty change is not on offer, so how are the so called legally irreversible changes going to be made when even the legal expert from the European Commission says that the Danish and Irish precedents are not valid.

Conservative Peter Lilley also called on the Government to deliver more than just 'symbolic' changes.

Senior Tory Bernard Jenkin said: 'After all the statements made by the Prime Minister, the Foreign Secretary, the former foreign secretary, about being in Europe but not run by Europe, the pledge to restore the primacy of national parliaments, the pledge to get an opt out from the charter of fundamental rights, to restore our borders.

'After all that - is that it? Is that the sum total of the Government's position in the renegotiation?'

But Mr Lidington replied: 'I think you underestimate how demanding, how far reaching, the proposals we have made will be.'

By far the biggest challenge to other EU countries is the demand for tougher limits on who can claim benefits from Britain's welfare system 'to reduce the numbers coming here'.

You must know that this is pretty thin gruel - much less than people had come to expect from the Government Tory MP Jacob Rees-Mogg

'We have proposed that people coming to Britain from the EU must live here and contribute for four years before they qualify for in work benefits or social housing,' Mr Cameron said.

'And that we should end the practice of sending child benefit overseas.'

He insisted that he understood that it would be 'difficult' for some EU countries, but he stressed that he has a mandate from the British people to enact changes set out in the Conservative Party manifesto 'to control migration from the European Union'.

But officials in Brussels were quick to point out that he stands little chance of getting a deal on benefits.

Martin Schulz, the president of the European Parliament, said: 'I've heard what the Prime Minister said. It is good that the UK's requests are now set out officially.

'I have strong doubts about the legality of the four year ban on access to welfare benefits for EU citizens but wait to see what specific ideas the British government will come up with in the end in this particular area.'

Mr Cameron insisted major changes were need as the price for keeping Britain in the EU, and warned his planned referendum could not be reversed, adding: 'Leave means leave'

WHAT ARE CAMERON'S KEY DEMANDS FOR EU REFORM? IMMIGRATION No in-work benefits or social housing until working migrants have been in Britain for four years. No child benefit or tax credits paid for children living outside the UK. No benefits for unemployed migrants, who could be deported if they do not get a job for six months. Restrictions on EU migrants bringing in family members from outside the EU Longer bans on rough sleepers, beggars and fraudsters returning to the UK Tougher rules on deporting foreign criminals Refusing to allow other countries to join the EU without imposing controls on the movement of their workers until their economies have reached UK levels Tougher and longer re-entry bans for fraudsters and people who collude in sham marriages. EUROZONE AND SINGLE MARKET Protection for the nine EU countries which do not use the euro from bailing out the single currency: Bulgaria, Croatia, Czech Republic, Denmark, Hungary, Poland, Romania, Sweden, and the UK. Would create a 'two-speed Europe' with eurozone countries moving closer, with those outside enjoying a looser relationship. But it would protect the single market. EVER CLOSER UNION Rewrite Brussels treaties to remove reference to 'ever closer union' which was supposed to entrench the idea that countries in the EU would move towards becoming a single political entity. Measures to strengthen national parliaments to club together to block Brussels diktats. COMPETITIVENESS Cut red tape for business and 'write competitiveness into the DNA' of the whole EU. Advertisement

European Commission spokesman Margaritis Schinas said there were some things in Mr Cameron's wishlist 'that are highly problematic as they touch upon the fundamental freedoms of our internal market'.

He added: 'Direct discrimination between EU citizens clearly falls into this last category.

'As President Juncker has repeatedly stated, we stand ready to work for a fair deal with Britain that is also fair for all the member states.'

Mr Schinas suggested other issues, like increasing the role of national governments, were 'feasible' but ensuring fairness between euro and non-euro countries could be 'difficult'.

The Prime Minister claims that the changes he wants on red-tape, protection from Eurozone problems and an end to EU integration are 'eminently resolvable' but critics say it is proof he has given up on trying to secure major reforms.

Mr Cameron has promised to renegotiate Britain's membership of the EU before holding an in-out referendum by the end of 2017.

He made clear that there would be no second referendum, and if the British people chose to leave the EU the decision would be final.

'If we vote to leave, then we will leave. There will not be another renegotiation and another referendum.

'If you think we should leave - and leave means leave - then campaign for that.

'But if you are actually arguing for a better relationship between Britain and the European Union, then don't campaign to get out. Work with me to get that better deal for Britain.''

Securing major changes could prove difficult as they will require the agreement of all 27 other EU countries, many of whom are opposed to limits on freedom of movement and allowing Britain to discriminate against their citizens.

Mr Cameron has spent this summer wining and dining prime ministers and presidents across the continent to win support for Britain, but has faced criticism for not actually spelling out in detail what he wants.

Today he sent his letter to European Council president Donald Tusk to demand curbing benefits for migrants, protecting Britain from the Eurozone and reining in Brussels red-tape.

He called for greater protection for the nine EU countries which do not use the single currency.

'Non-Euro members like Britain which are outside the Eurozone need certain safeguards, in order to protect the single market and our ability to decide its rules and to ensure that we face neither discrimination nor additional costs from the integration of the Eurozone,' Mr Cameron said.

'Because the European Union and the Eurozone are not the same thing and those of us who are in the EU but outside the Eurozone need that accepted.'

He wants to see 'clear and binding principles' that protect Britain and other non-Euro countries, including 'no discrimination and no disadvantage for any business on the basis of the currency of their country'.

On competitiveness, Mr Cameron demanded a target to cut the total burden on business and 'one clear commitment that writes competitiveness into the DNA of the whole European Union'.

Mr Cameron said that if he gets what wants he will campaign 'with all my heart and all my soul' for Britain to stay in the EU in his promised referendum but if they refuse to meet his demands, he will 'rule nothing out'

In a bid to limit the power of Brussels, Mr Cameron called for a 'new arrangement where groups of national parliaments can come together and reject European laws which are not in their national interest'.

This would not mean individual countries having a veto on every new law, but it would allow member states to club together to rejected Brussels diktats.

He also demanded 'a clear, legally binding and irreversible agreement to end Britain's obligation to work towards an ever closer union'.

If we vote to leave, then we will leave. There will not be another renegotiation and another referendum Prime Minister David Cameron

'That will mean that Britain can never be entangled in a political union against our will or be drawn into any kind of United States of Europe.'

In a major speech he insists that – if Europe shows 'political will and imagination' – he can secure substantial changes that will make it worthwhile for the UK to remain inside the EU.

He said: 'The European Union needs to change. It needs to become more competitive to cope with the rise of economies like China and India.

'It needs to put relations between the countries inside the Euro and those outside it - like Britain - onto a stable, long-term basis.

'It needs greater democratic accountability to national parliaments. Above all, it needs, as I said at Bloomberg, to operate with the flexibility of a network, not the rigidity of a bloc.'

Mr Cameron, pictured arriving at Chatham House this morning, insisted major changes were need as the price for keeping Britain in the EU

Handwritten notes on the PM's speech emphasised that he wants progress made on 'all 4 areas' and a 'legally binding' deal

To bolster his case, Downing Street last night released figures showing four in ten EU migrants rely on state handouts when they arrive in Britain.

Some 224,000 out of 526,000 new arrivals from Europe claimed benefits during their first four years in the country.

Tax credits were claimed by 144,000 while an estimated 10,000 families – many from Eastern Europe – pocketed at least £10,000 a year through in-work welfare in 2013.

Migrants entitled to in-work benefits claimed an average of £5,000 a family, costing the taxpayer £570million in 2013.

In a reference to the movie spy Ethan Hunt, who is played by Tom Cruise, Mr Cameron added: . 'There will be those who say – here and elsewhere in the EU – that we are embarked on Mission Impossible.

'I say: why? I do not deny that seeking changes which require the agreement of 27 other democracies, all with their own concerns, is a big task.

'But an impossible one? I do not believe so for a minute. When you look at the challenges facing European leaders today, the changes that Britain is seeking do not fall in the box marked 'impossible'.

'They are eminently resolvable, with the requisite political will and political imagination. The European Union has a record of solving intractable problems. It can solve this one. Let us therefore resolve to do so.'

As the prospect of the referendum inches closer, Mr Cameron was heckled yesterday at the CBI conference in a stunt organised by an anti-EU group.

He was trying to make the case for Britain staying in a reformed EU when two men waved a sign and shouted out that the CBI was the 'voice of Brussels'.

Students 19-year-olds Phil Sheppard and Peter Lyon were smuggled into the Grosvenor House Hotel in Mayfair, London after the Vote Leave campaign set up a fake company.

The group - which is vying to be the official voice of the campaign to leave the EU - has promised more similar stunts.

Mr Cameron will use a letter to European Council president Donald Tusk (right) to spell out what he wants on curbing benefits for migrants, protecting Britain from the Eurozone and reining in Brussels red-tape

Mr Cameron was yesterday heckled by Vote Leave campaigners at a CBI conference (pictured)

COUNTDOWN FOR CAMERON: HOW BRITAIN'S FATE WILL BE DECIDED Today Cameron to publish letter to European Council president Donald Tusk setting out Britain's demands. PM to give a speech warning Europe not to turn a 'deaf ear' to the UK. Tomorrow Major summit on migration begins in Valletta, Malta which will bring together EU leaders for the first time, giving Cameron chance to press the flesh and twist some arms in the margins. Next week European Council officials will begin arranging one-on-one meetings with representatives from each of the other 27 member states to see which of Britain's demands they will agree to, and which they will block. Thursday December 17 Cameron hopes to emerge from the last Brussels summit of the year with a deal which he can take back to the British people. May/June Ministers have ruled out holding the referendum on the same day as local and Scottish elections on May 5. EU allies are said to have been told June is Cameron's preference for holding the in-out referendum promised before the end of 2017. Advertisement

A summit in December between all European leaders will be the first big test of the renegotiation strategy.

If successful, and Mr Cameron is able to claim he has secured major concessions, the referendum could be held as early as next June or July.

But now the letter has been published today, the detailed negotiations will move to the offices of the European Council in Brussels.

Senior officials - known as 'sherpas' - from each EU member state will hold a series meetings with Mr Tusk's office about whether they will give Mr Cameron what he wants.

'They will go through one-to-one what their views are on the letter,' said a government source.

'So they will say 'we are happy with this one' or 'that one's a problem'. That is a process which has to happen for each of the 27 countries.'

Mr Cameron said say: 'I am in no doubt that for Britain the European question is not just a matter of economic security, but of national security too – not just a matter of jobs and trade but of the safety and security of our nation. I am not saying for one moment that Britain couldn't survive outside the European Union. Of course we could.

'Whether we could be successful outside the European Union is not the question. The question is whether we would be more successful in than out?

'Whether being in the EU adds to our economic security or detracts from it? Whether being in the European Union makes us safer or less safe? That is a matter of judgment.'

Mr Cameron said he has 'every confidence' that the UK 'will achieve an agreement that works for Britain', but added: 'If we can't reach such an agreement... then we will have to think again about whether this European Union is right for us.'

London Mayor Boris Johnson warned the talks will be tough. Speaking in Jerusalem, he told broadcasters: 'There will be a long period now of quite scratchy negotiations.

'I think there will come a great sort of juddering moment - there will be blood all over the carpet at some point in Brussels.

'I don't know when that will happen but I hope very much that we will get the deal by the end of next year.'

But critics were scathing about the lack of detail in Mr Cameron's six-page letter.

London Mayor Boris Johnson warned there will be 'blood on the carpet' in Brussels as Mr Cameron pushes for change

Ukip leader Nigel Farage: 'Clear that Mr Cameron is not aiming for any substantial renegotiation. No promise to regain the supremacy of Parliament. Nothing on ending the free movement of people. And no attempt to reduce Britain's massive contribution to the EU budget.

'His speech was an attempt to portray a new 'third way' relationship with Brussels that is simply not on offer.'

Vote Leave's Dominic Cummings said: 'David Cameron promised fundamental reform but what he's asking for is trivial, he's given up before he's started.

'The public wants the end of the supremacy of EU law and to take back control of our economy, our borders, and our democracy. The only way to do this is to vote leave – we won't get it by trusting Cameron.'

Vote Leave pointed out that, when Denmark was negotiating with the EU in 1992, it published a 251-page document setting out its demands.

Last night, Tory grandee Lord Lawson also tore into the PM's 'disappointingly unambitious' demands which he said 'don't seem to add up to a row of beans'.

The former chancellor, who is an out campaigner, told ITV News at 10: 'I believe he doesn't think he can get anything significant and therefore he is trying to catch the fish he can catch even though they are tiddlers.'

But supporters of Britain remaining in the EU welcomed the speech

Terry Scuoler, chief executive of EEF, the manufacturers' organisation, said: 'Now the Prime Minister has set out his stall, we need to see a swift resolution to negotiations and a commitment to a firm date for a referendum at the earliest opportunity.

'It is essential that we remove the uncertainty surrounding our future relationship with the EU and move forward.'

READ DAVID CAMERON'S LETTER TO BRUSSELS IN FULL