The incoming president of the European Commission has admitted he will have to change his team of commissioners, after opposition in the European Parliament.
Mr Barroso plans more consultation before deciding on a new line-up
Jose Manuel Barroso said necessary changes must be made, after postponing a crucial vote rather than face a veto.
Some MEPs were against the inclusion of Rocco Buttiglione, who has expressed controversial views on gays and women.
But Italy says that at present it is standing by its nomination of Mr Buttiglione as a commissioner.
However, the government said that Italian Prime Minister Silvio Berlusconi would talk to other European leaders to try to find a way out of the crisis.
Many MEPs were angry that Mr Buttiglione, who recently said he regarded homosexuality as a sin, had been put forward for the post of justice and home affairs commissioner.
Taking time out
A vote to approve the new commission was postponed on Tuesday after Mr Barroso withdrew his proposed line-up, saying more time was needed to choose a team that the parliament would approve.
"Necessary changes and sufficient changes must be
made in the team," Mr Barroso said after the parliamentary session.
The incoming leader said he is confident of winning support for a changed line-up.
But he declined to say whether he was planning to reshuffle his commission line-up and put Mr Buttiglione in a less contentious portfolio or ask Italy to propose another candidate.
"I believe that stopping the clock is the best way to find a solution in the best interests of Europe and its people," he told the news conference.
The BBC's European Affairs correspondent William Horsley says the postponement is a major victory for the parliament - the European Union's only directly-elected democratic institution - in its struggle for a bigger voice in running EU affairs.
Mr Barroso said he would consult parliament and EU leaders, who are responsible for nominating the commissioners, before putting forward new proposals "in the next few weeks".
Italian Foreign Minister Franco Frattini said Mr Buttiglione remained Italy's candidate.
Asked whether Italy would consider replacing him, he said: "This is a debate that will be subject to future reflection between the commission president and European heads of state. We certainly can't do it now".
The Italian press reported on Wednesday that Mr Buttiglione had already refused a request from Mr Berlusconi to withdraw his candidacy.
Mr Buttiglione's spokesman told the BBC there was no question of him standing down.
He is due to return to Rome on Friday, where the signing of the new EU constitution is likely to be overshadowed by the political storm.
The new commission had been due to start work on 1 November.
Incumbent commission leader Romano Prodi and his commission will now remain in office until a new team is approved, but there is no clear protocol on how to proceed.
Parliament President Josep Borrell said the EU was now entering "virgin political territory".
To applause from MEPs, Mr Barroso told parliament he believed the outcome of Wednesday's vote would not have been "positive for the European institutions or the European project".
Mr Buttiglione (left) has said he will not be standing down
Socialist floor leader Martin Schulz said the outcome was "a victory for the European Parliament, especially for my group".
Ulster Unionist MEP Jim Nicholson was among those who welcomed the decision to postpone the vote, but said the setback has not been helped by Mr Barroso's previous "inaction".
"This is a setback but it is not the end of the world, by any means," he said.
"However, I would have to add that MEPs will be looking at three or four other commissioners who do not appear to be up for the job."
The 732-member parliament cannot choose to reject Mr Buttiglione alone - deputies must accept or reject the new commission as a whole.
The 24 new commissioners were initially put forward by the governments of individual member states.