Liberal Democrat leader Charles Kennedy yesterday called on the Prime Minister to answer a "catalogue of charges" against him over Iraq.

At the Bournemouth conference, Mr Kennedy said Mr Blair should come before the Commons next month and make a statement explaining himself and his conduct.

But during a question and answer session, he stopped short of demanding the Prime Minister's resignation, despite demands earlier from a string of party activists.

"I don't think we have reached the resignation issue yet, until he has been in front of the Commons and given the account I am seeking," he said.

Mr Blair must answer "the extremely serious catalogue of charges that are mounting against him, not least the advice given to him by the Foreign Office about what was likely to happen in the aftermath of war", he said.

Mr Kennedy said: "Unless he can give a very definitive account, I think his position as Prime Minister is so tarnished that he would be effectively immobilised in that office."

During the 30-minute session, chaired by the editor of The Independent, Simon Kelner, Mr Kennedy denied there was a credibility gap in the party's spending plans.

He said treasury spokesman Vincent Cable was applying a very stringent slide rule to each and every commitment the party was entering into.

But it was on the thorny issue of the war against Iraq that many of the questions centred.

Asked if Mr Blair and President Bush should face war crimes charges, Mr Kennedy replied: ''I wouldn't jump to that conclusion.''

He said the Prime Minister should "come to the despatch box on day one (when Parliament reconvenes next month) and make a statement explaining himself and his conduct. He should conjoin that with an apology for the gross errors of judgement that have bedevilled this issue".

Asked if he would pull British troops back, the Liberal Democrat leader said: "Not as of yet."

He favoured instead a "planned phased withdrawal of British troops as the democratic timetable unfolds".

Mr Kennedy said he wanted to get to the truth on Iraq.

"I don't want the truth, on this occasion, to be left to the historians for generations to come.

"I want the truth established before the British people give the final verdict at the next General Election."