Mr Mandelson blames Mr Buttiglione for creating uncertainty

The proposed line-up for the commission has been withdrawn because of the row over Italian nominee Rocco Buttiglione.

Mr Buttiglione attracted controversy by calling homosexuality a sin.

Mr Mandelson - Britain's nominee for the Commission - said the revised line-up of commissioners would be stronger as a result of the row.

Italy says it is currently standing by its nomination of Mr Buttiglione as a commissioner.

BBC political editor Andrew Marr said Tony Blair was likely to put pressure on Italian premier Silvio Berlusconi to change his mind to resolve the deadlock.

The prime minister's official spokesman said: "We will do all we can to help but it's primarily a matter for Commission president Jose Manuel Barroso and the European Parliament."

'Mild indigestion'

The European Parliament had been due to vote on Wednesday on whether to accept or reject the whole commission.

But Mr Barroso said more time was needed to choose a line-up which MEPs would endorse.

Mr Buttiglione has really got to put himself right with Parliament and his colleagues or choose to withdraw Peter Mandelson MEPs force Barroso retreat

Some MEPs were against the inclusion of Rocco Buttiglione, who recently said he regarded homosexuality as a sin, and had been put forward for the post of justice and home affairs commissioner.

Mr Mandelson tried to play down the impact of the row on the commission's future and praised Mr Barroso for holding his nerve.

He told BBC Radio 4's PM programme: "It is a hiccup today, or worse, mild indigestion, so that is not brilliant.

"But as a result the Barroso commission Mark Two will be stronger."

'Creating uncertainty'

Mr Mandelson said it would be unacceptable if people with strong religious convictions could not become commissioners.

But he argued: "Mr Buttiglione didn't help himself by creating uncertainty about how he would apply his beliefs, his religious convictions, to the portfolio for which he was responsible.

"People were not sure whether he would come with pre-set ideas and prejudices and a determination to rewrite the policy handbook and take policy in a different direction as a result of those beliefs."

The former MP said the problems were prompted by Mr Buttiglione's comments after he was given the justice brief by Mr Barroso.

He argued: "It really is a matter for Mr Buttiglione. He has created the uncertainty.

"His succession of comments and interventions since his original parliamentary hearing have added to the problem, not helped resolve the situation.

"He has really got to put himself right with Parliament and his colleagues or choose to withdraw, whatever he wishes to do."

Leftward shift?

British Labour MEPs' leader Gary Titley said proposals were now needed that could win broad support.

"We have now reached the stage where he [Mr Buttiglione] cannot be a candidate for the commission."

But Jonathan Evans, leader of the British Conservative MEPs, was worried Mr Barroso had succumbed to a "left-wing witch hunt".

He said left-wing MEPs had picked on Mr Buttiglione in an attempt to change the political direction of the commission.

Liberal Democrat MEPs' leader Graham Watson said the parliament had asked for respect for its judgement.

"At every stage, our willingness to stand by that judgment was doubted and mistrusted and tested - tested to the edge of political crisis," he added.

Outgoing British Commissioner Neil Kinnock argued it was now best for Mr Buttiglione's name to be withdrawn as a reshuffle would be technically and politically difficult.