Charles Kennedy has been warned by some of his closest allies that he has as little as three months to save his leadership as support for the Liberal Democrat leader appeared to be waning among MPs and activists. Even Mr Kennedy's most loyal backers are now conceding that he must "raise his game" by the party's spring conference in March or stand down.
Mr Kennedy will attempt to stage a fightback tomorrow when he appears on ITV's Jonathan Dimbleby programme. But soundings taken by The Independent among grassroots activists suggest many share concerns about Mr Kennedy's lacklustre performance.
Mr Kennedy's deputy, Sir Menzies Campbell, in effect put him on notice to improve, when he called on the party leader yesterday to "raise his game". Sir Menzies denied being responsible for anonymous briefing against Mr Kennedy, but made it clear his support depended on the leader operating "at the top level".
Sir Menzies said: "There is absolutely no doubt that the Liberal Democrats are at their best when they are led by Charles Kennedy in full flight.
"He himself has told us all that it is necessary to raise our game and he included himself in that. I want him to stay as leader, operating at the top level of the full range of his abilities."
He told the BBC: "He has got as long as he wants as leader ... I am happy to continue to serve Charles Kennedy as I have since he became leader in 1999."
Sir Menzies said he would relish a confrontation with the Conservatives under David Cameron. "Bring them on. I am ready to compete with Mr Cameron on ground which the Liberal Democrats know very well and Charles Kennedy has staked out."
The new Tory leader has moved to exploit turmoil in Liberal Democrat ranks by making an open appeal for the party's rank and file to defect to the Conservatives.
He used a speech in Hereford to declare himself a "liberal Conservative" and urge Liberal Democrat MPs and activists to switch sides. "I say to Liberal Democrats everywhere: we're on the same side now."
He said Conservatives and Liberal Democrats now shared common ground on issues from the Iraq war to the environment. "There is a new home for Liberal Democrat voters, and so a real prospect of a change in government."
Mr Kennedy hit back, accusing Mr Cameron of opportunism and insisting that he should join the Liberal Democrats. He said: "I'm delighted David Cameron is acknowledging that my party under my leadership was right all along about such key issues such as Iraq and the environment."
Mr Cameron's comments were widely interpreted as an invitation for Liberal Democrats to join an anti-Labour electoral alliance. The Conservatives have already worked closely with the Liberal Democrats on several key policy areas, such as green issues.
Allies of Mr Kennedy are urging him to sack MPs suspected of briefing against him. But there was a sense of gloom amongst some of his staunchest supporters. A senior Kennedy ally said: "I want Charles to survive. But it is difficult to guarantee him keeping the job beyond the spring unless he gets a grip on things."
Mr Kennedy faced further pressure yesterday as he was questioned about his drinking habits during an interview on BBC Radio 4. He insisted: "I think people have to judge by results, the results under my leadership for my party are good and I don't think it's an issue."
About half of the councillors or local officers contacted by The Independent yesterday expressed reservations about his leadership. Dan Daley, a member of Kent County Council and Maidstone District Council, said: "It is sad. I think it is time for him maybe to move on ... He says all the right things and pushes the right buttons but his television appearances don't do him any good.
"He doesn't come across as a charismatic leader."
Deborah Yamanaka, a councillor from Wrington, Somerset, said a leadership contest would "clear the air". She said: "He does not appear to be forceful enough. He is softly spoken and not a Paddy Ashdown type."
But Geoff Dale, a councillor from Totnes in Devon, said: "I'm absolutely disgusted with the MPs who are doing this. I have every confidence in Charles Kennedy."Reuse content