Nick Clegg yesterday used part of his first conference speech as leader of the Liberal Democrats to praise the party’s candidate for Mayor of London.

He called Brian Paddick “an outstanding candidate who will transform London.”

His endorsement came on the same day that extracts from Mr Paddick’s autobiography Line of Fire were serialised in a newspaper he once sued.

The Mail on Sunday chose to dwell on the former senior police officer’s sexuality.

Among the new facts to come to light from the Mail’s story are that Mr Paddick was physically assaulted by a boyfriend and that he first knew he was gay when he was ten.

“After I took my A-levels in the summer of 1976, my parents expected me to go to university but instead I joined the police,” he wrote.

“I knew that the force would be homophobic but it provided both the perfect cover and necessary encouragement for me to keep my sexuality under wraps.”

Mr Paddick details his heterosexual and homosexual sexual encounters and describes how he came out to his wife of five years and his elderly parents.

Line Of Fire goes on sale on March 25th.

Mr Clegg used his keynote speech at yesterday’s conference in Liverpool to announce that he will not become a member of either a Labour or Tory-led coalition in the event of a hung parliament.

“Will I ever join a Conservative government?,” he asked.

“No. Will I ever join a Labour government? No.

“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. So for anyone who shares our ambitions I have two words: join us.”

Mr Clegg’s speech, which was greeted with a standing ovation by the party faithful, came at the end of a week which saw his new leadership directly challenged.

He ordered his MPs to abstain from a vote on a referendum on the Lisbon Treaty.

Almost a quarter of Lib Dem MPs, including three front benchers who resigned from their positions, defied him.