LONDON (AFP) - Britain moved closer to a referendum on Europe on Thursday after a eurosceptic lawmaker from Prime Minister David Cameron's Conservative party won the chance to put forward a law guaranteeing a vote by the end of 2017.
Parliament will now formally debate the EU referendum bill as early as July after backbench Conservative MP James Wharton came top of a ballot to see which lawmakers may put forward so-called private members' bills.
The bill was rushed out by the Conservative party earlier this week in response to the growing threat of a rebellion by eurosceptic Tory MPs who doubt the prime minister's commitment on the issue.
The Conservatives are having to rely on Wharton alone to put forward the bill - instead of the party as a whole - because their partners in the coalition government, the Liberal Democrats, are pro-Europe and would not support it.
Although there is no guarantee that the bill will get the necessary parliamentary time to actually go to a vote after the debate, the fact that it is the first on the ballot gives it a greater chance.
Cameron has previously vowed to renegotiate Britain's relationship with Brussels and then hold an in-out referendum by the end of 2017, provided that he wins the next general election in 2015.
But Conservative eurosceptics want him to enshrine that promise in law before the election to stop any backtracking, as well as to head off the rise of the anti-EU UK Independence Party (UKIP).
The bill requires a referendum to be held before December 31, 2017 on the question: "Do you think that the United Kingdom should remain a member of the European Union?" Conservative sources quoted in British media said there would be a "three-line whip" - the strictest orders used by parliamentary parties in Britain to enforce discipline - to get Tory MPs to support it.
The eurosceptics dealt Cameron a bloody nose on Wednesday when more than a third of the party - including Wharton - voted in favour of a parliamentary motion expressing regret that there was no mention of a referendum in the coalition government's plans for the next year.
The motion failed because the Liberal Democrats and the opposition Labour party both voted against it, as did a majority of Conservatives.