Reform the price of Lib Dem support

Only the offer of a "new type of government" could tempt him to join forces with Labour or the Tories in the event of a hung Parliament, he said in his first conference speech in charge.

He also committed the party to seeking tax cuts - pledging to spend any spare cash on reducing individuals' bills rather than boosting public services.

"Everybody wants to be in our gang. So I want to make something very clear today: will I ever join a Conservative government? No. Will I ever join a Labour government? No," he told activists in Liverpool.

"I will never allow the Liberal Democrats to be a mere annex to another party's agenda. But am I interested in building a new type of government? Yes. Based on pluralism instead of one party rule? Yes. A new system, that empowers people not parties? yes.

"We want a new, more liberal Britain and the Liberal Democrats will be the gathering point for everyone who wants that liberal Britain too - no matter their background, no matter their party."

Sources close to the leader said Mr Clegg would happily work with either party but that he would not settle simply for places at the Cabinet table in a traditional coalition.

And the conditions attached - while not yet set out - would go far beyond traditional demands for the introduction of proportional representation in Westminster elections, he indicated.

It is another sign that Mr Clegg is prepared to be more open than recent predecessors about tactics in the event of no party having an overall majority after the next general election.

Mr Clegg made only a joking reference to the bruising Commons rebellion by almost a quarter of his MPs over the Euro referendum which shook his leadership last week. But he issued a warning that the party could only succeed in fighting the establishment parties and vested interests "if we are united and if we are disciplined".