Cameron Faces Parliament Showdown over EU Referendum

British Prime Minister David Cameron faced a showdown with eurosceptic rebels on Wednesday in a parliamentary vote over his plans for a referendum on membership of the European Union.

Up to 100 disgruntled backbenchers from Cameron's Conservative party are set to vote for a motion expressing "regret" that the coalition government has failed to enshrine in law the promise to hold an in/out referendum.

The vote is non-binding, but if the rebellion is as big as expected it will deal a fresh blow to Cameron's authority and renew concerns among Britain's international partners and investors about its position in the EU.

The Conservative rift is bad news for the party two years before a general election, and a reminder of how the issue of Europe led to the downfall of late former prime minister Margaret Thatcher and undermined her successor John Major in the 1990s.

Cameron, who will miss the vote because he is visiting the United States, has insisted he is "profoundly relaxed" about it. He has said his MPs have a free vote but ministers must vote against or abstain.

Parliamentary speaker John Bercow approved the motion earlier Wednesday and allowed it to be the subject of a vote.

It expresses regret that legislation promising a referendum was not included in last week's Queen's Speech, in which the government set out its program for the year.

Cameron argues that he wants to renegotiate the conditions of Britain's membership of the EU and then, if he is returned to power in the 2015 general election, put the question to the people in a referendum by the end of 2017.

But the Tory eurosceptics are flexing their muscles by demanding that he enact legislation before the next election.

Many fear they will lose ground to the anti-EU and anti-immigration UK Independence Party (UKIP), which had its best-ever performance in recent local authority elections.

The motion is certain to be defeated because Cameron's coalition partners the Liberal Democrats and the opposition Labor party will both predominantly vote against it.

Liberal Democrat Deputy Prime Minister Nick Clegg, standing in for Cameron at the weekly prime minister's questions session in parliament, accused the Conservatives of "shifting the goalposts" in the row over the EU.

Cameron tried to quell the rebellious mood in his party on Tuesday by publishing a draft bill revealing the wording of a referendum.

But because the Liberal Democrats will not back such a bill the Conservatives are having to take the unusual step of getting a single lawmaker to push it through parliament -- a prospect that is unlikely to happen.

The leader of the main opposition Labor Party, Ed Miliband, said Cameron had "completely lost control" of his party on the issue.

In a sign of the deepening turmoil, Nadine Dorries, one of the rebels, told the Spectator magazine she was considering running at the next election on a joint ticket between the Conservatives and the upstart UKIP.

Dorries' comments come just weeks after she ended a six-month suspension from the Conservative party for appearing on a jungle reality show in which she completed humiliating tasks including eating ostrich anus live on national television.

Under the provisions of the one-page draft EU (Referendum) Bill, voters would be asked the question: "Do you think that the United Kingdom should remain a member of the European Union?"

Labor opposes legislating now for a referendum in four years, although it too is divided over Europe.

The vast majority of Labor lawmakers will oppose the amendment on Wednesday, although a small number have signed up to it.

A Guardian/ICM poll published this week found 35 percent of Britons favored an immediate referendum. Some 43 percent said they would vote to leave the EU and 40 percent said they wanted to stay in.