We really have to start confronting people with the increasingly headcase agenda of William Hague

Charles Kennedy

Mr Kennedy's declaration came the same day opinion polls suggested, for the first time in eight years, that Labour had lost its lead over the Tories.

The polls fuelled speculation of a hung parliament after the next election - expected to be held next spring - in which the Lib Dems would hold the balance of power.

'Unfit to govern'

Speaking at a fringe meeting of the New Radicalism group, Mr Kennedy said one of the conference's key goals must be to hammer home the message that Mr Hague was unfit to govern.

"There is disillusion with the government, self-evidently," he said. "But we really have to start confronting people with the increasingly headcase agenda of William Hague."

Mr Kennedy attacked the opposition leader for "bending to every passing fad ... playing on every prejudice", be it on asylum, health, law and order or education.

"If William Hague was in government - God forbid - tomorrow, you can't actually govern the country on the basis of that kind of headcase agenda," he told the meeting.

"I want that message to come out of this conference loud and clear."

He cautioned against reading too much into the latest polls, forecasting they would turn out to be a "blip" caused by the sudden springing up of the fuel crisis.

"Last week was obviously a spectacular, unusual week," he said. "Therefore, we would expect some blip by way of response in terms of public opinion.

"The amazing thing is that all they [the Conservatives] managed to do, after the worst week that any democratic government has had for 20-plus years, is to get level."

Lib-Labbery played down

A number of conference delegates raised the contentious issue of relations with Labour, calling on the Lib Dem leadership to pull out of the Joint Cabinet Committee (JCC) in which they hold talks on constitutional issues with government ministers - described by one delegate as "morally bankrupt".

But Mr Kennedy played down the JCC's significance saying it had met just twice in the past year.

"I always prefer, instinctively, to be in the room, at the table in discussion than to choose to be outside," he said.

"We keep it to the constitutional reform agenda, if there's something to talk about. If there is not something to talk about, then we don't bother.

"It has been given a sort of mythical status which in my experience is not deserved."

Despite signals to the contrary from Labour in recent months, Mr Kennedy insisted that private discussions with Tony Blair had persuaded him that the prime minister had not ditched a promise to at least hold a referendum on proportional representation for Westminster.

He said that Mr Blair was facing a fight within Labour, however, over the issue.