A majority of British people would vote to leave the European Union in the wake of the migrant crisis engulfing the continent, a shock new Mail on Sunday poll has found.

If a referendum were to be held tomorrow on whether to remain a member of the EU, 51 per cent of British people would vote ‘No’.

It follows a string of polls over recent years which have given comfortable leads to the pro-European camp. Significantly, it is the first measure of public opinion since the Government changed the wording of the referendum question, lending weight to claims that the new phrasing boosts the chances of victory for the ‘Out’ campaign.

The survey also found strong backing for David Cameron’s stance in standing up to German Chancellor Angela Merkel, who wants the UK to take in a greater share of migrants.

Growing public support to cut all ties with Brussels came as it was revealed the Prime Minister told Merkel to her face: ‘I could walk away from the EU.’

At a private dinner in Downing Street, Merkel accused him of being ‘too forceful’ in demanding concessions from the rest of the EU. That was why ‘we all hate you and isolate you,’ she said.

David Cameron suffered his first defeat in the build-up to the Brexit referendum campaign after being told to rewrite the allegedly biased question to be put on the ballot paper.

Mr Cameron agreed to change the wording after the Electoral Commission objected to the suggestion that voters be invited to say Yes to Britain staying in the European Union.

Eurosceptics celebrated the verdict. Nigel Farage, leader of the UK Independence party, said: “I’m in no doubt that the Yes/No offering was leading to great confusion.”

The EU referendum bill going through parliament had proposed voters be asked: “Should the United Kingdom remain a member of the European Union?”

But the independent Electoral Commission urged the government to change the question to: “Should the United Kingdom remain a member of the European Union or leave the European Union?”

Pro-EU campaigners shrugged and said they would continue to call themselves the Yes campaign. One said: “In any case the word “remain” sounds static: fighting for the status quo is an advantage.”

The Electoral Commission said the original wording was clear but contained a “double bias” by including only the “remain” option and having the “yes” answer endorse the status quo.

Research from pollsters ICM and ComRes suggests that voters are more likely to say they favour the status quo when framed as a yes or no question rather than whether the UK should remain or leave.

David Cameron and his advisers are urging the UK’s business leaders not to speak out in favour of the country remaining in the EU, for fear they will jeopardise the prime minister’s sensitive renegotiation of Britain’s terms of membership ahead of a referendum.

One ally of Mr Cameron’s said that the government had been clear in its message to business to “shut up [on a British exit] until a deal is done with the EU”.

A poll in the Mail on Sunday by Survation found 43 per cent of people in favour of Brexit — against 40 per cent backing the status quo: suggesting a significant shift towards euroscepticism.

The prime minister’s team is concerned that if business leaders speak out now in favour of remaining in the EU they risk damaging the renegotiation process as well as potentially turning public opinion against continued membership. One person close to Downing Street’s thinking said that Mr Cameron felt public statements by UK companies at this point would be “counterproductive”.