Sir Menzies broke his silence to issue a statement offering Mr Kennedy his full support for as long as he remained in charge, in response to accusations that he was undermining the party leader.

These arose after he refused to comment when asked if he backed his leader as he emerged from a meeting with Mr Kennedy in his Commons office on Wednesday. Mr Kennedy held similar meetings with all his senior spokesmen to confront widespread concerns over his leadership.

Sir Menzies said pointedly in his statement that he had abided by an agreement not to speak about the meeting. “Unlike others, I followed the advice of the Chief Whip and Mr Kennedy’s own office not to comment on private conversations with him,” he said. “I do not have any intention of standing against Charles Kennedy.”

The significance of his comments was not what they contained, since talks among Mr Kennedy’s critics have focused on urging him to quit and not on organising a challenge, but that he had to make them at all. Two MPs angrily said that Sir Menzies was the victim of a manoeuvre to blame him for this week’s events, which would benefit Mr Kennedy as well as Simon Hughes and Mark Oaten, the contenders in any leadership contest.

In a clear contrast to Sir Menzies’s initial silence, Mr Hughes took to the airways yesterday, offering his own carefully worded support for Mr Kennedy. Asked if he wanted and expected Mr Kennedy to stay in charge, he replied only: “That is my expectation.” Asked again if that was what he wanted, Mr Hughes said: “Yes, because I want Charles to build on the success he has had.”

Mr Hughes confirmed that there had been concern and frustration with Mr Kennedy among MPs, but said that the leader had indicated that he would listen. Mr Kennedy, who travelled to Brussels to visit the European Liberal group of MEPs, continued to insist that he had the backing of the overwhelming majority of his MPs and would stay as leader. Asked if he would try to remove Sir Menzies, he said, “No”, adding: “Your best friends are very often your most frank friends. You don ’t stop being friends.”

Several Lib Dem MPs told The Times that the party was now in limbo, given that several had told Mr Kennedy directly that he should go. In further signs of recriminations, however, critics began to accuse some other colleagues of a failure of nerve in their one-to-one meetings with him.

Those who did tell him that it was time to go were uncertain if he would let them continue on the front bench. Mr Kennedy said that he was not planning immediate changes but told BBC Radio 5 Live that those not willing to serve him could go. “I have said very clearly to people that if they have profound or insuperable difficulties and they feel they can’t stay then that’s unfortunate but we’ve got plenty of talent around these days more than capable and willing to fill any vacancies that arise,” he said.

But coded criticism of his leadership continued. Susan Kramer, the Lib Dem MP for Richmond Park, told The World at One on BBC Radio 4 that he was an outstanding leader “on his good days”.

Alistair Carmichael, MP for Orkney & Shetland, said that the party had lacked drive and direction since the election and Mr Kennedy could stay on provided that assurances he had given to his MPs were met.

• Charles Kennedy’s survival hopes were dealt a blow last night with a new poll showing he is losing the support of voters.

  The YouGov poll for The Daily Telegraph found that only 11 per cent of people thought he would make the best Prime Minister — down 7 per cent since the general election in May.

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