It seems to me that because in June 1998 sponsorship was offered by the Hinduja Foundation for the Dome that coincided with a point where Mr Mandelson made his telephone call

Andrew Lansley

But the row continues to grow over whether he pulled strings to help Srichand Hinduja secure a British passport after he agreed to sponsor the Millennium Dome.

Mr Mandelson faces the Commons later on Wednesday when he is due to answer Northern Ireland questions, shortly before Tony Blair receives what is expected to be a rough ride over the actions of his close confidant at prime minister's questions.

Conservative Cabinet Office spokesman Andrew Lansley has called for an inquiry into Mr Hinduja's passport application.

"It seems to me that because in June 1998 sponsorship was offered by the Hinduja Foundation for the Dome that coincided with a point where Mr Mandelson made his telephone call to [Home Office Minister] Mike O'Brien," he said.

'Above board'

After a day in which Labour voices willing to back the Northern Ireland secretary were thin on the ground, Scottish Secretary John Reid insisted that Mr Mandelson's actions were entirely above board.

Mr Hinduja is said to have approached Mr Mandelson

And Home Office Minister Charles Clarke told the BBC: "As with anything that comes along, it is far and away the best thing to tell the full story as openly as possible at the outset."

"The one thing I am certain of is that the Home Office's processes in relation to this have been extremely rigorous and will continue to be."

After days of damaging reports on the nature of Mr Mandelson's precise involvement in Mr Hinduja's passport application, the cabinet minister had launched his own defence with a round of interviews on Tuesday.

He insisted he had not pulled any strings to influence the Home Office decision to grant the passport after Mr Hinduja and his brother, Gopichand, had raised the prospect of significant Dome sponsorship.

The passport was granted soon after the donation had been pledged.

Denials, U-turns and contradictions

The Conservatives and the Liberal Democrats have called into question Mr Mandelson's fitness to serve in the cabinet.

We want to be convinced that nothing improper took place

Michael Ancram

On Monday, Downing Street had insisted that Mr Mandelson had made no direct approach to the Home Office and that Mr Hinduja's query over his passport applicaitonr had been dealt with at civil servant level.

But the following day the prime minister's official spokesman admitted that in fact Mr Mandelson had personally discussed the issue over the telephone with Mr O'Brien.

The Hinduja brothers had already suggested financing the Dome's faith zone to the tune of �1m when Mr Mandelson intervened in June 1998.

Mr Mandelson stressed he had not endorsed the passport application - Mr Hinduja had previously been turned down - but simply asked Mr O'Brien whether it could be resubmitted under new rules.

The former immigration minister was approached

Mr Mandelson insisted there was "no wink or nudge" involved in the "innocent inquiry" he made on Mr Hinduja's behalf.

The result of the row so far has been damaging newspaper headlines calling Labour's onetime spin doctor supreme a liar and demanding his resignation.

'Common sense by-pass'

Conservative Party Chairman Michael Ancram called on all the records relating to the affair to be made public, including civil service notes.

"Mr Mandelson is a past master at shifting his ground and having the truth dragged out of him inch by inch," he told the BBC.

"We want to be convinced that nothing improper took place."

People now wanted to know how long Mr Blair was going to "stand alongside his slippery friend", Mr Ancram added.

The Blairs with Hinduja

Liberal Democrat Norman Baker said that the episode was looking "increasingly murky for Mr Mandelson" and that the government appeared to be backtracking.

"Clearly Mr Mandelson is in this deeper than first admitted. He has clearly behaved improperly for a minister.

"The prime minister should reflect on whether he merits a cabinet post if Labour is re-elected."

Independent MP Martin Bell accused Mr Mandelson of having had "a common sense by-pass".