Peter Mandelson's fight to clear his name has reignited the Hinduja passport affair and provoked reports of a feud between two of the prime minister's closest advisers.

The affair erupted after Sunday newspapers reported the prime minister's official spokesman Alastair Campbell describing Mr Mandelson as "slightly detached" and casting doubt over his state of mind.

In response, Mr Campbell denied that he had "knifed" Mr Mandelson, who resigned after giving contradictory accounts of his part in the passport application of a wealthy Indian businessman.

To present this as an attack on his state of mind, let alone a knifing, is absurd

Alastair Campbell

Mr Mandelson has given his own version of events, denying that he had lied and insisting that he had been rushed into resigning for an insignificant error.

As well as leading to the resignation of one of Mr Blair's closest advisers, the passport affair has put another minister under a cloud and raised questions of undue influence by Mr Campbell.

'Media frenzy'

In a statement, Mr Campbell dismissed any suggestion of a feud between the two most prominent shapers of New Labour's media image.

"The press reports of my briefing to the Sunday papers provide further evidence of the current media frenzy," said Mr Campbell.

"To present this as an attack on his state of mind, let alone a knifing, is absurd."

But Sunday Times journalist Michael Prescott insisted that the press had not misrepresented Mr Campbell's words.

He challenged Downing Street to make public a recording made by press office staff.

'Disgraceful behaviour'

The opposition Conservative Party, scenting an issue that could turn round their election fortunes, have stepped up the political pressure.

Mandelson has pledged to clear his name

"This is disgraceful behaviour from Downing Street, turning on Peter Mandelson like this purely to protect the prime minister," said Conservative Party chairman Michael Ancram.

"The Blair government, built as it is on spin, lies and deception, is unravelling."

His colleague, shadow home secretary Ann Widdecombe said the spotlight must now turn on to the Home Office to establish how ministers there had reacted to Mr Mandelson's approach in connection with the Hindujas' passports.

For his part, Liberal Democrat leader Charles Kennedy warned that politics was in danger of losing credibility among voters.

"We are all tarred with the same brush. It is very, very corrosive. It only takes a rotten apple or two and suddenly the whole barrel begins to stink," he said.

'A small mistake'

Mr Mandelson has pledged to clear his name in the inquiry into the affair by former Treasury solicitor Sir Anthony Hammond QC.

Writing in the Sunday Times, Mr Mandelson said he had stepped down in a "moment of weakness" as pressure mounted for an explanation in the face of "incomplete" facts.

"A small mistake, a failure to focus on a small matter, had turned into a monumental disaster," he said.

"I know I have a mountain to climb before reversing this error, but I know I have to start somewhere."

But Mr Mandelson former colleagues have cast doubt on his comments.

Home Secretary Jack Straw questioned Mr Mandelson's claim that he had not lied.

There is no doubt, by his own admission, that he told an untruth

Jack Straw

"There is no doubt, by his own admission, that he told an untruth," he said.

Another Labour minister, International Development Secretary Clare Short said Mr Mandelson had problems with the truth.

"He wasn't accurate, didn't speak the truth, let himself down and the government. Peter Mandelson is over," she said.

One of the wealthy brothers at the centre of the controversy, SP Hinduja, said he had "done nothing wrong" in merely asking Mr Mandelson about the progress of his application.

Mr Hinduja said he was perfectly justified in approaching both Mr Mandelson, Europe Minister Keith Vaz and "other individuals" to check the progress of his passport application.

The Hinduja brothers are at present in New Delhi being questioned over the Bofors arms scandal involving alleged kickbacks.