Faced with mounting pressure from hardline euro-sceptic Tories, Prime Minister David Cameron on Wednesday pledged an “in-out” referendum on Britain’s membership of the European Union (EU) if his party won the next general election in 2015.

Ironically, even as he claimed that “today, public disillusionment with the EU is at an all time high”, an opinion poll showed that there had in fact been a dramatic reversal in public opinion in recent weeks with the number of Britons wanting to stay in Europe overtaking those in favour of withdrawal.

In a much-awaited speech, Mr. Cameron said he wanted Britain to stay in Europe but on its own conditions. These included clawing back powers from Brussels in a number of areas. Though he did not spell out the areas, these are known to include immigration, employment and banking.

He said that he would negotiate a new settlement with the EU, and would put it to a vote. A referendum would be held latest by 2017.

“It is time for the British people to have their say. It is time to settle this European question in British politics. I say to the British people: this will be your decision. And when that choice comes, you will have an important choice to make about our country’s destiny,” he said.

“It will be an in-out referendum.”

The announcement came amid growing concern among Tories that they were losing support to the pro-referendum U.K. Independence Party (UKIP).

Mr. Cameron insisted that he was not a “British isolationist” but was opposed to a federal EU “superstate”.

“I never want us to pull up the drawbridge and retreat from the world. I am not a British isolationist but I do want a better deal for Britain,” he said.

If he was able to negotiate a better deal, he would campaign for a “yes” vote in a referendum “with all my heart and soul”. He warned that Britain must think “very carefully” about the implications of pulling out of the EU.

“If we left the European Union, it would be a one-way ticket, not a return,” he said.

Criticism

Critics, including business leaders and his Liberal Democrat coalition partners, warned that the move would “condemn” the British economy to years of uncertainty. The Opposition Labour leader David Miliband accused Mr. Cameron of putting his party interests above national interests.

Britain’s EU allies said it could not “cherry pick” or unilaterally change the rules of its membership.

“Say that Europe is a soccer club. You join this soccer club, but you can’t say you want to play rugby,” said the French Foreign Minister Laurent Fabius.

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