Boris warns Britain will be trapped 'hook, line and sinker' in an unreformed EU if voters reject Brexit as top Tories line up to condemn Cameron's 'bullying' campaign

• Boris Johnson today warned Britain would be like a frog in a boiling pan
• Iain Duncan Smith claims 'spin, smears and threats' delivered by No10 
• And Liam Fox warns party has to come back together and reunite in June
• The PM had to deny a conspiracy to keep Britain in the EU yesterday

By Tim Sculthorpe, Mailonline Deputy Political Editor

Britain would be trapped 'hook, line and sinker' in an unreformed EU if voters reject Brexit in June, Boris Johnson warned today.

In a new attack on David Cameron's deal, the London mayor said Britain would be like a 'frog in the boiling saucepan of water' unable to escape greater political integration. 

Mr Johnson's fierce new attack on Mr Cameron's renegotiation efforts come after Iain Duncan Smith warned the Prime Minister to cut out 'dodgy dossiers' and 'bullying' from his EU campaign.

Boris Johnson launched new attacks on David Cameron's deal today, insisting it would leave Britain in an unreformed EU 

Iain Duncan Smith, left, attacked the 'spin, smears and threats' being deployed by the Government machine to 'bully' Britain into remaining inside the EU, while Liam Fox warned the party had to come back together in June

Liam Fox today warned the 'ramped up' infighting between senior Tories would make it more difficult to reunite the party and govern after the referendum in June.

The blistering new row comes a day after Mr Cameron was forced to deny a 'conspiracy' to keep Britain inside the EU amid claims he had orchestrated a row over the 'jungle' migrant camp in Calais. 

In an interview with the Evening Standard, Mr Johnson warned: 'We will never be able credibly to argue for any reform in Europe again.

'We will be signed up to this thing lock, stock and barrel — hook, line and sinker.'

He said the conclusions of Mr Cameron's renegotiation, painstakingly hammered out with the EU a fortnight ago, offered 'no real change' to Britain.

Former defence secretary Dr Fox made a series of interventions today, speaking on the fringes of the Scottish Conservative Party conference and doing a series of media interviews.

He hinted for the first time the Prime Minister might have to quit if the 'peasants revolt' and vote for Brexit despite the onslaught from the In campaign.

His remarks after Mr Duncan Smith, writing in today's Daily Mail, delivered a devastating attack on the 'spin, smears and threats' being issued by the Government machine.  

Mr Fox told the BBC today: 'The Conservative Party is in a position where we will have to come back together to govern the country after the 24th of June.

'And the difficulty we will face is that if the arguments have been ramped up too much in that initial period that will become harder for us.

David Cameron, pictured in Scotland today, faced warnings from senior Conservatives not to 'ramp up' attacks on party colleagues during the referendum 

'How easy or how hard it is for us to come together and govern this country as a majority party is largely dependent on how well we treat one another, and the respect with which we treat one another, in the run up to the referendum.'

Mr Fox today insisted the claims from the In campaign were all 'nonsense'.

He said: 'The whole point behind Project Fear is it has to be credible.

'We need to have some credible stories, we need to have some credible statistics and the sort of cases we've had that you'll not get cheap flights, children's books won't get published, you'll not be able to be rescued if you're stranded abroad – this is all nonsense.'

Mr Fox repeated his warnings on Twitter today and at a speech on the fringes of the Scottish Conservative Party Conference 

He insisted the Tories were not yet at the point where unifying on June 24 was impossible. 

Asked if Mr Cameron could stay in Downing Street if the Brexit camp win, Mr Fox said: 'Yes, constitutionally, of course.

'I've been saying for a long time to my colleagues they need to understand the binary nature of a referendum, the fact it will arouse a lot of passions.

IN CAMPAIGN LAUNCHES NEW 'GRAB A GRANNY' TACTIC  

Young voters are much more likely to back EU membership 

Younger voters are being urged to steer their grandparents away from the Brexit door in a new campaign tactic dubbed 'grab a granny'.

The Remain campaign wants to tap into the belief voters in their 20s and 30s - the so-called EasyJet generation - are more pro-EU because they take much greater advantage of cheap flights, easy communication and the ability to live and work across Europe.  

The 39-year-old Education Minister Sam Gyimah is to spearhead the campaign ahead of the EU referendum on June 23.

He told The Times: 'This is a generation that has lived its entire life while the UK has been in the European Union.

'This is the generation that takes for granted the fact that on a weekend they can weigh up a flight going to Manchester or Madrid.

'They carry everything on their smartphone. Through Facebook they communicate with three times the population of Europe.'

Mr Gyimah insisted the referendum was more important for the young as they still had their entire lives ahead of them.

He added: 'The EU can be incredibly annoying and frustrating from a national government perspective but after thinking about it quite hard I came to the view that it’s a bit like being in a relationship.

'If all you ever looked at was what you gave and the sacrifices you are making, but not the give-and-take element, most of us would end up as singletons.'

'In fact I'd said to a number of my colleagues that in a referendum friendships get tested, relationships can sour.' 

Today's row comes a day after Mr Cameron was accused of orchestrating a bitter row over whether the French would tear up a bilateral borders agreement and move the Calais 'jungle' camp to Kent.

At a press conference with French President Francois Hollande yesterday, Mr Cameron was forced to deny there was a 'David Icke-style conspiracy' to keep Britain in the EU.  

Mr Duncan Smith warned of lasting damage to British politics beyond the June 23 referendum if Mr Cameron and the other leading players in the Remain camp do not conduct the debate in a more 'respectful manner'.

Mr Duncan Smith said: 'After all, such desperate and unsubstantiated claims are now being made that they begin to damage the very integrity of those who make them in the eyes of the public.' 

In a series of so-called dodgy dossiers, the Government has set out a nightmarish Brexit scenario which could lead to 'a decade or more of uncertainty', destroy trade and even stop Britons holidaying around Europe. Mr Duncan Smith said this 'bullying' campaign was designed to distract attention from the fact Mr Cameron had secured no meaningful reform to the EU.

He points out that, at his Bloomberg speech in 2013, the Prime Minister himself had said that staying in an unreformed Europe would make the country weaker.

In his Mail column, ex-Tory leader Mr Duncan Smith argues that, given EU reform has not been achieved, Mr Cameron's own logic should point the country towards the exit door.

In one of the post powerful interventions in the EU debate so far, he said: 'Ask yourself this: with razor wire fences going up in mainland Europe due to fears of unsustainable levels of migration, with the failing euro creating economic misery for Europe's poorest people, with high unemployment and economic stagnation, is this a set up you would seek to join?'

His comments reflect growing anger among MPs and ministers in favour of leaving the EU at the Government's tactics.

Senior figures say the country is being denied the mature debate the country was promised by the PM.

On Wednesday, Foreign Secretary Philip Hammond triggered fury by claiming that Out campaigners are secretly content to 'sacrifice' British jobs in order to regain control of our borders.

He was also accused of 'scaremongering' over claims two million UK citizens living in the Costa del Sol and elsewhere in the EU could be forced to return home.

 

Time to halt the smears spin and threats: IAIN DUNCAN SMITH 

Two weeks after the Prime Minister returned from Brussels with his EU deal, the debate on the European Union has shifted significantly. The Remain campaign's case seems almost wholly based on what they describe as the nightmare of leaving. This case has in whole or in part become characterised by spin, smears and threats.

This was not what we were told the debate would be about and so for those keen to stay in the EU I register a concern and also a challenge.

In the last fortnight we have had a series of highly questionable dossiers – threatening almost biblical consequences if we dare to consider a future outside of the European Union.

We've seen a series of stunts, whereby big businesses, big banks, and powerful politicians from other EU member states seek to bully the British people into believing their jobs and security are at risk. The impartiality and integrity of the civil service – on whose credibility the whole institution of Government depends – has even been called into question by Parliament.

The Secretary of State for Work and Pensions warned of lasting damage to British politics beyond the June 23 referendum if PM David Cameron (pictured) does not conduct the EU debate in a more 'respectful manner'

The acrimonious manner in which all this has been conducted is troubling, and will I fear have consequences long beyond June 23. After all, such desperate and unsubstantiated claims are now being made that they begin to damage the very integrity of those who make them in the eyes of the public.

The biggest danger to the European Union comes not from those who advocate departure, but from those who denounce such thinking as heretical and dangerous.

WE MUST LEAVE THE EU TO ESCAPE THE RED TAPE, BUSINESS CHIEF WARNS  

The head of one of the biggest groups representing small and medium-sized firms came out in favour of leaving the EU yesterday.

In a strident attack on the Prime Minister's 'deal' with Brussels, British Chambers of Commerce director general John Longworth, right,  said the EU remains 'essentially unreformed' and is 'incapable of meaningful reform'.

He added the risks of staying in such a club were 'as daunting' as leaving, telling the Daily Mail: 'I have analysed the facts personally and my view is we should leave.'

The intervention is a bruising setback for David Cameron and Chancellor George Osborne, who are desperate to get business leaders to back the In campaign.

Mr Longworth, a former executive at Tesco and Asda, said the Prime Minister's deal with Brussels 'fell far short of our expectations'. 

He warned that staying in an unreformed EU would leave Britain 'sitting on the margins' as the eurozone integrates further.

Saying the UK would have a 'brighter economic future outside the EU', he urged business leaders to look beyond any short-term disruption and think about the future they want for their children and grandchildren.

Mr Longworth also pointed out that by 2010, European red tape was costing British business £80bn a year. 'Since then there has been major costs added by Europe,' he said. 

'The one thing that Sajid Javid [the Business Secretary] cannot do anything about is European legislation and that is where the bulk of the burden is coming from.' 

His comments, at the annual conference of the BCC in London, make Mr Longworth the first leader of a major business group to take on the Prime Minister over the referendum.

Unlike the pro-EU Confederation of British Industry, which is seen as the voice of 'big business' and was a supporter of Britain joining the euro, the BCC represents 75,000 small and medium-sized businesses with millions of staff across the country.

This is the most important question we have faced in a generation, and it is vitally important that the debate is conducted in a respectful manner – where we maturely interrogate the issues, rather than indulge in scaremongering.

And so that brings me to the challenge.

In January 2013, the Prime Minister made an excellent speech, setting out his vision for a reformed European Union. He made a powerful case for 'fundamental, far-reaching change' – without which he said the EU 'would make our countries weaker not stronger'.

Now, I know that the Prime Minister entered the negotiations with good intent. He said at the time that 'with courage and conviction, I believe we can deliver a more flexible, adaptable and open European Union'.

The problem was that he was faced with the final reality that the EU is disinclined to make such fundamental reform.

Now there will be some people who will have believed from day one that we should stay in the Union regardless, and others who may have wanted to leave irrespective of any changes that might have been secured.

However, the original referendum challenge set by the Prime Minister was not predicated on whether we wanted to remain in the EU or not – it was whether we wanted to remain in a 'reformed EU'. That is a vital distinction and one which is now being deliberately avoided.

After all, the Prime Minister said himself that the case for staying in was conditional on achieving reform. So for those who are undecided, surely the paramount question that they will want to answer for themselves is whether the European Union that we now have is reformed or not.

If they arrive at the conclusion that it has not, then it would be quite logical for them to decide that Britain would be better served Out.

Perhaps that's why the terms of the debate seem to have been shifted by the Remain camp. They no longer seek to pretend the Prime Minister's deal amounts to fundamental reform.

Instead, the question being asked seems to be whether we could cope on our own at all. Why they would seek to present our country, and themselves, as so weak is beyond me.

But ask yourself this: with razor wire fences going up in mainland Europe due to fears of unsustainable levels of migration, with the failing euro creating economic misery for Europe's poorest people, with high unemployment and economic stagnation, is this a set up you would seek to join?

If the answer is no, then we as a country should have the confidence that, as the fifth largest economy in the world, we can have a more prosperous and more positive future if we take control of our own destiny.

We should not be intimidated into forgoing that choice.

Indeed, as the Prime Minister himself said in that same 2013 Bloomberg speech: 'Of course Britain could make her own way in the world, outside the EU, if we chose to do so.'

Some people are now determined to make out that if Britain were to leave, all the potential scenarios would be perilous. If that really were the case, wouldn't it have been deeply irresponsible for the same people to have put the question to the British people in the first place?