THE prospect of David Cameron’s emergency brake could lead to a surge of EU migrants coming to Britain seeking to beat the deadline on welfare curbs, according to a senior Tory colleague.

Former leadership contender David Davis pointed out that since the proposed deal had been set out "Eastern European newspapers have carried numerous stories about in-work benefits and the plans to terminate them for the first four years after a migrant's arrival in the UK" while Brussels has suggested that the scheme could take 12 months to implement.

"Under such circumstances," argued the Yorkshire MP, "the incentive for anybody wishing to come to live in the UK will be to come as quickly as possible to beat the deadline when any such restrictions come into effect. Accordingly, we are likely to see a surge in migrants in the next 12 months."

Former cabinet minister Sir Eric Pickles, another Eurosceptic who now looks likely to support the Prime Minister's deal, said: "What we need to be clear about is we're not trying to prevent people moving inside the European Union."

Instead, he said, the reforms were aimed at preventing people gaining "something for nothing" by gaining benefits before contributing to the UK.

Douglas Carswell, Ukip's only MP, has urged senior Conservatives including Michael Gove and Boris Johnson to publicly back Brexit in the forthcoming referendum, stating it would be "wonderful to have them on board".

But it was suggested Mr Cameron had made a personal plea for Mr Gove to stay with the In camp as the Scot is said to be torn between his personal loyalty to the PM and his anti-EU beliefs.

Elsewhere, it was said Work and Pensions Secretary Iain Duncan Smith, a prominent Eurosceptic widely expected to campaign for Brexit, had told friends Mr Cameron's deal was a "load of rubbish", which would be challenged in the European courts.

In a separate development likely to boost the position of Mr Cameron, Lord Powell, one of Margaret Thatcher's closest advisers, suggested the former premier would have backed his proposed deal for a new relationship with Brussels.

But Lord Tebbit, the ex-Tory chairman, dismissed Lord Powell’s claim, saying he knew her views better than his fellow peer did and that if she were alive, she would be saying No, no, no.