LibDem frontbenchers rebel against leader on EU vote

LONDON (Reuters) - Three Liberal Democrat frontbenchers are expected to resign their shadow cabinet posts late on Wednesday when they defy leader Nick Clegg and vote in favour of a referendum on the European Union treaty.

Clegg has ordered Lib Dem MPs to abstain in a vote on a Conservative amendment that calls for a referendum on the Lisbon treaty but a number are set to break ranks.

The disagreement on the vote, expected around 7 p.m., has raised serious questions about Clegg's fledgling leadership.

"I personally have made an undertaking to my constituents that when this issue came to the Commons I would vote for a referendum," Lib Dem environment spokesman Tim Farron told Sky News. "I shall do so and I'll face the consequences."

Rules of collective cabinet responsibility mean the shadow ministers must resign their posts if they defy against their leader's orders.

Justice spokesman David Heath and Northern Ireland spokesman Alistair Carmichael are also expected to quit.

Farron said he would be surprised if more than three Lib Dem frontbenchers resigned, although some party backbenchers are expected to vote with the Tories.

The government is still expected to win the vote because not enough Labour MPs are expected to rebel.

Clegg wants his MPs to abstain on the Conservative amendment because he wants to force a referendum on whether Britain should be part of the European Union or not.

Clegg argues that EU membership is the heart of the matter.