Charlie Whelan said on Monday morning he would give up his job as soon as an "appropriate opportunity" became available.

Shortly after, the one surviving spin doctor from Labour's election-winning team blasted the media for their obsession with government spokespersons.

The prime minister's official spokesman, Alastair Campbell, insisted: "What really matters in Government are the policies we are implementing."

BBC Political correspondent John Pienaar: Press attention should be on Euro not spin, says government

Mr Whelan also described the attention focused on rumours about his involvement in the recent home-a-loan scandal as "absurd".

But, in a statement, he said he could not longer carry on at his present job.

"I want to make it absolutely clear that I was not responsible for disclosing any information about Peter Mandelson's mortgage and I refute any suggestion that I was.

BBC Business correspondent Ed Crooks: "With Charlie Whelan you were always hearing Gordon Brown's thoughts"

"I do however take the view that the job of press secretary becomes extremely difficult if the press secretary, and not the department he serves, becomes the story and the subject of excessive attention.

Speculation has surrounded Mr Whelan's future at the Treasury following the row over the downfall of former trade secretary Peter Mandelson.

Mr Whelan returned to work on Monday after spending 10 days out of contact after allegations he leaked information that led to the resignation of Mr Mandelson.

Home loan: Peter Mandelson's controversial house

Mr Mandelson quit after it was revealed he had received a secret loan of �373,000 from then paymaster general Geoffrey Robinson to help buy his London home. Mr Robinson also resigned.

Like Mr Mandelson and Mr Robinson before him, Mr Whelan left his job still insisting he had done nothing wrong.

The prime minister's spokesman also said there was "no evidence" Mr Whelan had leaked against the former trade secretary.

He added that he did not believe Mr Whelan was the source.

Sir Bernard Ingham: "He has been a liability from day one"

The Guardian newspaper, which broke the story, itself took the unusual step of stating its information did not come from the chancellor's office.

But some Cabinet ministers had been reported to have been demanding Mr Whelan's resignation.

In a number of areas, Mr Whelan's departure is being treated as just rewards for previous briefings against Labour ministers, even if he is innocent in this case.

Gordon Brown is now seeking a new spokesman

Mr Whelan's departure from the Treasury comes as The Mirror newspaper revealed details of a memo to Chancellor Gordon Brown from Mr Mandelson asking him not to stand for the Labour leadership in the wake of John Smith's death in 1994.

The Mirror denies that the memo was leaked to journalist Paul Routledge by his close friend Charlie Whelan.

Mr Routledge told BBC Radio 4's World at One he thought Mr Whelan did not hold him responsible for the end of his Treasury career.