No challenge to Clegg, and certainly not from Huhne

Nick Clegg's potential successors rallied around him yesterday, killing off any suggestion that his leadership was under threat following the party's drubbing in local elections.

But the question is bound to return if the Lib Dems' agony is prolonged.

Four MPs could harbour dreams of replacing him, were Mr Clegg to be forced out of office. Each man has his admirers and each would have to overcome serious problems to step up to the top job. Chris Huhne, the Energy Secretary, has been the most vociferous Liberal Democrat minister in taking on his Tory colleagues over their brutal campaign against the alternative vote (AV).

His aggressive stance will have pleased the Lib Dem faithful still struggling to reconcile themselves with the creation of the coalition.

However, a third leadership bid by Mr Huhne could be overshadowed by reports about his private life. Yesterday he was forced to deny claims from his wife, from whom he is separated, that he asked another person to take driving penalty points on his behalf for a speeding offence. Mr Huhne left Vicky Pryce, to whom he was married for 26 years, for a former Liberal Democrat aide. Ms Pryce, an economist, is now writing a book about their marriage.

The Business Secretary, Vince Cable, has also made little secret of his distaste for his Conservative partners, describing them after the AV vote as "ruthless, calculating and thoroughly tribal".

His attack will have been music to the ears of party activists, many of whom regard him as a near-visionary.

But his halo has been tarnished after a traumatic opening to his governmental career. He faced ridicule for his indecisive stance on the tuition fees policy being introduced by his department. He was then humiliated after boasting to undercover reporters posing as constituents that he had "declared war" on Rupert Murdoch. And Mr Cable's age, 67, could count heavily against him.

There is no such problem for the party's 40-year-old president, Tim Farron. Yesterday he insisted he would be standing "shoulder to shoulder" with Mr Clegg in the fight for "radical and progressive" policies.

He is on the Left of the party and was among 21 Liberal Democrats to vote against the Government in the totemic tuition fees vote. But he still must prove himself as a political heavyweight. Simon Hughes, the Liberal Democrat deputy leader, is on the same wing of the party and is regarded by some left-minded activists as its conscience. Yesterday he was insisting that the coalition plans to overhaul the NHS should not go ahead without "fundamental change".

His critics would argue his appeal to Tory-leaning voters would be severely limited.