Speaker defiant on debate outburst

He won some endorsement from both Downing Street and Tory leader David Cameron, but was condemned by Liberal Democrat leader Nick Clegg.

"I think the Speaker got it wrong, very wrong," he said.

"It is clear Parliament as a whole owes an apology to the British public. He needs to reflect that sense of apology and the urgency for new rules that put MPs beyond any further suspicion."

Mr Martin's conduct was again openly questioned in the Commons chamber when he was asked to apologise for comments he made to ex-minister Kate Hoey.

In a point of order, senior Labour MP David Winnick said it had been "inappropriate" for Mr Martin to refer to Ms Hoey's "pearls of wisdom on Sky News" after the former minister suggested that calling in the police to investigate the leaks was an "awful waste of money". Mr Martin rejected the call for him to apologise for such "personal comments".

Tory MP Douglas Carswell is seeking six fellow MPs to support a no-confidence motion in an attempt to oust Mr Martin.

But the Speaker's position appeared to be safeguarded when Tory leader David Cameron later said it "goes without saying" that he supported Mr Martin. "I think it's a very important constitutional principle that the Opposition supports the Speaker's office and the role of the Speaker," he told a press conference.

Gordon Brown's spokesman, when asked to endorse Mr Martin, said: "The Speaker is appointed by the Commons, not the government. The Prime Minister obviously supports the will of the Commons, therefore he supports the person who has been elected as Speaker of the Commons.

"The Prime Minister has said before and he stands by that, that he thinks the Speaker is doing a good job. But these are not really matters for him, these are matters for the House of Commons."