David Cameron has said the British people must “have their say” on Europe as he pledged an in/out referendum if the Conservatives win the election.
The prime minister said he wanted to renegotiate the UK’s relationship with the EU, before asking people to vote.
The British people would face a “very simple choice”, he stated, either to accept the result of the talks or to leave the EU altogether.
Labour said Mr Cameron was “weak” and being driven by “party interest”.
In a long-awaited speech, Mr Cameron pledged to hold a referendum during the early part of the next parliament – by the end of 2017 at the latest – if the Conservatives win the next general election.
He said it would be a decision on the UK’s “destiny” and, if he secured a new relationship he was happy with, he would campaign “heart and soul” to stay within the EU.
“It is time for the British people to have their say,” he said. “It is time to settle this European question in British politics. I say to the British people: this will be your decision.”
However, Mr Cameron did not spell out what powers he would like to see the UK take back as part of a new settlement or what would happen if the negotiations did not go his way.
‘Very simple choice’
The Conservative leader has been under pressure from many of his MPs to give a binding commitment to a vote on Europe.
Mr Cameron said “disillusionment” with the EU was “at an all time high” and “simply asking the British people to carry on accepting a European settlement over which they have had little choice” was likely to accelerate calls for the UK to leave.
“That is why I am in favour of a referendum,” he said. “I believe in confronting this issue – shaping it, leading the debate. Not simply hoping a difficult situation will go away.”
Setting out the conditions for a future poll, he said he would seek a “mandate” for a renegotiation and a referendum in the next Conservative election manifesto.
“And when we have negotiated that new settlement, we will give the British people a referendum with a very simple in-or-out choice to stay in the EU on these new terms; or come out altogether. It will be an in/out referendum.”
But he said holding such a referendum now would be a “false choice” because Europe was set to change following the eurozone crisis and it would be “wrong to ask people whether to stay or go before we have had a chance to put the relationship right”.
Mr Cameron said he “understood the appeal” of Britain going it alone and he was sure the UK would survive outside the EU. But, he said, the UK must think “very carefully” about the implications of withdrawal for its prosperity and role on the international stage.
“If we left the European Union, it would be a one-way ticket, not a return,” he added.
The prime minister rejected suggestions that a new relationship was “impossible to achieve”, adding that he would prefer all other EU countries to agree a new treaty but would be prepared to seek negotiations on a unilateral basis.
Conservative MPs who want a looser relationship with the EU have said they are “satisfied” with its contents.
Douglas Carswell told the BBC it was the speech he had “been waiting to hear from a Conservative prime minister all his adult life” while Mark Pritchard said it was “a major triumph” and would unite his party over the issue.
‘Threatening to leave’
But the former European commissioner and Labour cabinet minister Lord Mandelson told the BBC that Mr Cameron was putting forward a “completely bogus and rather phoney set of demands and circumstances” designed to appease critics in his party.
Labour said the referendum pledge defined Mr Cameron “as a weak prime minister, being driven by his party, not by the national economic interest”.
“We understand the need for change but I don’t honestly believe the best way to get change in a club of 27 is to stand at the exit door demanding change or threatening to leave,” shadow foreign secretary Douglas Alexander said.
The Lib Dems say pursuing a wholesale renegotiation of the UK’s membership will cause uncertainty.
“The prime minister’s efforts to reconcile his own position with that of his eurosceptic backbenchers leads logically to the position that if he could not get what he wanted out of Europe, he would be willing for the UK to leave,” said its former leader Sir Menzies Campbell. “This will hardly commend his approach to those in the EU whose co-operation he requires.”
The UK Independence Party said the “genie was out of the bottle” about a possible exit from the EU.
“Winning this referendum, if and when it comes, is not going to be an easy thing but I feel that Ukip’s real job starts today,” said the party’s leader Nigel Farage.”
John Cridland, director general of employers group, the CBI, said “closer union of the eurozone is not for us” but Mr Cameron “rightly recognises the benefits of retaining membership of what must be a reformed EU”.
The speech, which has been in the planning for six months, had been scheduled for last Friday in the Netherlands, but was postponed because of the Algerian hostage crisis.