British Prime Minister David Cameron's Conservative party published on Tuesday a draft bill for a referendum on EU membership, setting out the question and saying that it must take place before the end of 2017.
"Do you think that the United Kingdom should remain a member of the European Union?" is the wording of the question that would appear on ballot papers, according to the proposed bill.
The bill also states that the referendum must be held before December 31, 2017.
Cameron agreed to publish the bill in a bid to head off the growing turmoil engulfing his party on the issue of Europe.
Many eurosceptic Conservative lawmakers want greater commitment from him before general elections that are due in May 2015.
He has previously promised to renegotiate Britain's relationship with the European Union, but had said he would only enact legislation for a referendum after the 2015 election.
But the draft bill published Tuesday is highly unusual because it has been published by the party, not the government, and will rely on an individual Tory MP guiding it through parliament as a private members' bill.
It is also almost certain to fail because of opposition from the Liberal Democrats, the Conservatives' junior partners in the coalition government, and from the opposition Labour party.
The publication of the draft bill may however placate some in the Conservative party a day before many of its MPs were expected to vote for a separate parliamentary motion condemning the coalition's European policy.