The incoming President of the European Commission, Jose Manuel Barroso, has unveiled a new list of proposed commissioners.
He withdrew his first team after it become clear that the European Parliament was likely to reject it.
Barroso: "It is better to take time to get it right"
Q: What caused the problem?
The immediate cause of the row was Rocco Buttiglione, the Italian politician nominated as European commissioner for justice and security.
His conservative views on homosexuals and women led the European Parliament's civil liberties committee to vote against him, for the first time ever in the assembly's history. However, Mr Buttiglione was approved by the legal affairs committee.
Eventually, Mr Buttiglione yielded to pressure and resigned. Latvia also withdrew its nominated commissioner and put forward a new one.
The episode has seen MEPs flexing their political muscles as never before.
Whether the EU will regain some of its public credibility as a result is less clear. Mr Barroso faces a tough five years. He will have to work very hard to regain the confidence of the Socialists, Liberals and Greens in the European Parliament, whose complaints about Mr Barroso he initially ignored.
Q: What was the row all about?
To some, the Buttiglione row was another episode in last year's confrontation between the leader of the Socialist group in the European Parliament, Martin Schulz, and the Italian Prime Minister, Silvio Berlusconi, who compared Mr Schulz to a Nazi concentration camp guard.
Mr Schulz and his group vowed to vote against the European Commission unless Mr Berlusconi's protégé stepped down.
But Mr Buttiglione was not the only designated European Commissioner criticised by the MEPs.
The Dutch businesswoman Neelie Kroes (a Liberal), set to take over the powerful portfolio of competition commissioner, showed insufficient grasp of details and raised doubts about her future independence in the post. But Mr Barroso has decided to keep her.
The former Hungarian foreign minister Laszlo Kovacs (a Socialist) also failed to convince MEPs that he knew enough to become an effective European Commissioner for energy. He has been moved to taxation.
The former Latvian parliamentary speaker Ingrida Udre (a eurosceptic Green), designated as taxation commissioner, did not provide enough clarification about past allegations of financial irregularities. She has been replaced by Andris Piebalgs, a former finance minister, who Mr Barroso now proposes for the energy portfolio.
The Christian Democrats, who make up the biggest parliamentary group, did not call for the resignation of any of the first line-up of commissioners, in order to show their support for Mr Barroso, who is also a conservative.
Q: What does the EU Commission do?
It is more than simply a civil service for the EU - it is the only body that can propose legislation.
Legislation is then amended and passed, or rejected, by the EU Parliament, jointly with the Council of Ministers, which represents the member governments. MEPs also scrutinise the work of the commissioners.
The Commission is sometimes seen as the driving force behind European integration, but is ultimately under the control of the member states. Each commissioner is in charge of a policy area, such as agriculture or enlargement.
Commissioners are appointed by the member states, and are usually senior politicians. However, their job is to act in the general European interest, not to advance the interests of their own country.
Q: How much power do the MEPs have?
The MEPs opposed to Mr Buttiglione were delighted with Mr Barroso's climbdown over his first proposed line-up of commissioners, seeing this as a decisive shift in the EU's power structure - a victory for the European Parliament, which has proven that it has real muscle.
The parliament, which confirmed Mr Barroso in a separate vote this summer, cannot reject individual commissioners. According to the Nice Treaty, it votes on the European Commission "as a body."
The European Parliament's rules of procedure make clear that it "shall elect or reject the Commission by a majority of votes cast," so abstentions do not count.
The vote is taken by roll-call, unlike the vote for the commission president, which was secret.
The European Parliament's powers have been strengthened over the years. But the right to nominate or reject individual commissioners rests with the commission president and EU governments - even in the European Constitution, which was signed by EU leaders in Rome on Friday.
None of the current EU treaties explains what should happen in case the entire commission is rejected.
The only precedent is the fall of the European Commission led by Jacques Santer in 1999 over allegations of nepotism and loss of political control. But that was a year before the end of its mandate, whereas the Barroso Commission has not even taken office.
Q: Why didn't Mr Barroso simply find someone else to replace Mr Buttiglione?
It is not up to him to nominate the members of his team. The decision was taken by each of the 25 EU governments, after consultations with Mr Barroso. He did persuade them to nominate more women than ever before - eight out of 24. But none of the governments gave him a choice of candidates. The only room for manoeuvre he had was in the distribution of portfolios.
Q: Didn't Mr Barroso try to appease the MEPs?
In a letter to Mr Barroso, Mr Buttiglione expressed regret over the problems caused by his confirmation hearing and said he was strongly opposed to discrimination of any kind.
Mr Barroso followed this with several compromise proposals.
He offered to set up a new European agency for human rights and to launch an action plan on discrimination.
He said he would take away Mr Buttiglione's powers in these sensitive areas and transfer them to a group of several commissioners led by Mr Barroso himself. And he rejected plans for transit camps for asylum seekers in North Africa - an Italian government proposal.
But he refused to give in to the parliament's main demand, arguing that a reshuffle of the commission at this stage would cause more problems than it would solve.