MPs reacted furiously when they discovered that Paul Tyler, the party's Chief Whip, had indicated his determination to stand in the race to succeed Paddy Ashdown. In theory, Mr Tyler is in charge of enforcing the party's ban on any leadership campaigning before 11 June, when Mr Ashdown formally steps down.
Allies of the Cornwall North MP claimed that he was the only realistic alternative to Charles Kennedy, the party's agriculture spokesman and clear front-runner in the undeclared contest. Mr Tyler's move follows the decision last week of Menzies Campbell, the Liberal Democrat foreign affairs spokesman, to pull out of the race.
The Tyler camp claimed that he was a "big candidate" who would enter the fray in the hope of thinning the already-crowded field of runners. As well as Mr Kennedy, the current list of hopefuls includes Don Foster, MP for Bath, Jackie Ballard, MP for Taunton, David Rendel, MP for Newbury, and Simon Hughes, MP for Southwark North and Bermondsey.
With Mr Campbell finally out of the race, all of the other candidates are now claiming that they are the "main challenger" to Mr Kennedy. But senior Liberal Democrat figures are understood to be concerned that the party risks looking ridiculous unless the field can be narrowed to three or four candidates. Mr Tyler's opponents yesterday denounced his plans to run and derided his claim that he was a "heavyweight" candidate capable of beating Mr Kennedy.
Many are furious because Mr Tyler has reprimanded them for speaking to the media before the contest starts officially on 12 June, after the European elections.
Lembit Opik, MP for Montgomeryshire and one of Mr Foster's strongest supporters, was so incensed that he attacked Mr Tyler publicly yesterday. "Paul Tyler as Chief Whip has been the man to set the rules for the leadership campaign. It's a little bit like the umpire running on to the pitch and trying to tackle the other players for the ball," he told BBC Radio 4's Today programme.
"The logic of thinning the field by adding your own name to it does escape me. The issue is that Paul Tyler is the man who has berated us week after week for actually bringing up the subject of the leadership at all." Des Wilson, the former Liberal Democrat general election campaigns chief, said that Mr Ashdown himself had to accept some of the blame for the "mess" of the leadership contest.
"How can it be that after 11 years of one leader that no successor has emerged? I think that Paddy Ashdown has to take some responsibility for this. It's been very much a one-man band," he said.