The controversial incoming EU Justice Commissioner, Rocco Buttiglione, has voiced regret over damaging comments he made about homosexuals and women.
Many Socialist MEPs want Mr Buttiglione's nomination withdrawn
"I deeply regret the difficulties and
problems that have arisen", the Italian said in a letter to Commission President Jose Manuel Barroso.
Mr Buttiglione is reported to have relinquished powers concerning discrimination and sexual harassment.
MEPs have threatened to veto the whole 25-member Commission over the row.
Pressure on Barroso
Despite Mr Buttiglione's letter, the leader of the Socialist group in the European Parliament, Martin Schulz, insisted that Mr Barroso reallocate the commissioner portfolios.
"My group is demanding a reshuffle of the commissioners," he said.
During a confirmation hearing two weeks ago, Mr Buttiglione said he regarded homosexuality as a "sin", and that marriage existed to allow women to have children and the protection of a male.
He was also reported as having said single mothers were not very good people.
In his letter to Mr Barroso, quoted by Reuters, he said "I did not intend in any way to offend the feelings of anybody".
Mr Barroso met European Parliament leaders in a bid to secure support for a crucial confidence vote next Wednesday.
He said he appreciated "the enormous importance parliament attaches to fundamental rights" and pledged to set up a panel of commissioners "to look into questions of fundamental rights and non-discrimination".
"I am taking personal charge of coordinating our actions in this area," he said.
"The new commission wll be absolutely opposed to any kind of discrimination based on sexual orientation, gender, religious beliefs," he pledged.
"It is not reasonable to allow a commission to fall because two or three commissioners are inadequate. If the MEPs take a balanced view they will see that I the commission president have taken account of their concerns and they should recognise that the consequences of a negative vote would be worse than those of a positive one."
Several parties are threatening to reject the whole commission unless the nomination for justice commissioner is withdrawn.
But Danish MEP Jens-Peter Bonde, who was at the meeting with Mr Barroso, was quoted as saying "there will be no reshuffle" of the new commission.
Earlier, Mr Buttiglione said he had been quoted out of context, and claimed he was the victim of a "hate campaign".
His comments at the hearing incensed the Socialists, the Greens and some liberals, who said he was not fit for the new post, which entails supervision of discrimination issues, including the rights of women and gays.
Danish Socialist Poul Nyrup Rasmussen said there was "now a risk that the Commission could be voted down next week".
The 268-strong conservative European People's Party - the largest in parliament - firmly backs Mr Buttiglione.
But nearly half of all MEPs are believed to be against the Barroso commission if Mr Buttiglione is allowed to stay in his job - the 200-strong Socialists supported by the Greens, eurosceptics and other leftists, Reuters news agency reports.
The outcome could depend on the assembly's Liberal group, the third largest. They are seen as split on whether to accept that Mr Buttiglione remains as justice commissioner.