Not since it helped to bring down the European Commission led by Jacques Santer in 1998 has the European Parliament felt such a surge of power in its veins.
There were scenes of confusion, commotion and jubilation as a hyperventilating parliament, just an hour or so before it was due to vote on the new commission, heard its president withdraw his team and ask for more time to put together a better one.
President Jose Manuel Barroso had done his sums overnight. He had the support of the centre-right European People's Party, but not of many others.
It is back to the drawing board for Mr Barroso (left)
His meeting on Tuesday evening with the centrist Liberal Democrats had failed to win them round, making it highly likely that the entire commission would be sunk.
In a short speech to MEPs, Mr Barroso admitted that he would lose the vote and plunge the EU into crisis.
He asked for more time to think and to consult EU national leaders - several of whom may now have to propose new candidates for the commission.
It is the Italian nominee, Rocco Buttiglione, with his conservative views on homosexuality and women, who has caused the most fuss. But the impending reshuffle may have to go much wider.
Nominees in doubt
At a news conference Mr Barroso said it was his intention to change "what is necessary, what is sufficient" in his team before resubmitting it to parliament.
What will happen next in this unprecedented institutional row is that Mr Barroso will first have to decide to what extent a change of portfolios among his team will do the trick, and to what extent completely new faces will be required.
The centre-right European People's Party, which would have supported the proposed team, has made it clear that it will not be happy with a new team from which only Mr Buttiglione is excluded.
For many outsiders it will remain a mystery why Mr Buttiglione did not do the honourable thing and withdraw several days or even weeks ago
It had objected to other commissioners-designate - some of whom had the support of the socialists - and will want to see them replaced too.
That means the cull could include not only Mr Buttiglione, but Laszlo Kovacs, the Hungarian who failed to convince his hearing he had sufficient knowledge about the energy sector; Ingrida Udre, the Latvian who was to take charge of taxation; Mariann Fischer-Boel, the proposed agriculture commissioner from Denmark; and Neelie Kroes, the much-criticised Dutchwoman who was to take the competition portfolio.
If Mr Barroso decides that all of these nominees must go, then he will have to ask the respective governments to put forward new candidates.
He will then have to review his entire team of 24 men and women and decide how to redistribute the portfolios.
Four other would-be commissioners have vexed MEPs
Those who are either new candidates or being offered different portfolios will then have to undergo hearings before parliamentary committees.
And finally, the European Parliament will vote on the entire team.
It could be a long process, though Mr Barroso said he hoped it could be done in a few weeks.
Meanwhile, the current commission under Romani Prodi's captaincy will continue to guide the European ship of state.
The debacle comes at a crucial time for the European Union. Heads of government meet in Rome on Friday to sign the controversial European Constitutional Treaty, thereby launching the campaign for its ratification across the continent.
For many EU citizens, the row will not signify a victory for the parliament - as many MEPs see it - but simply another European mess.
As for the authority of Mr Barroso, seriously challenged even before he takes office, he himself shrugged it off. He said he felt his political authority had even been reinforced, because he had shown he could listen to criticism and draw the consequences.
Mr Buttiglione's brief spell in the limelight will surely be over soon. It is suggested that the Italian Foreign Minister, Franco Frattini, or the present Italian commissioner, Mario Monti, might be put forward instead.
Mr Buttiglione's withdrawal will be a humiliation for the Italian Prime Minister, Silvio Berlusconi.
But for many outsiders it will remain a mystery why Mr Buttiglione did not do the honourable thing and withdraw several days or even weeks ago, as soon as he saw the writing was on the wall for him.
Some ask why Rocco Buttiglione has not withdrawn his candidacy
Had he done so, many red faces would have been avoided, and the European Parliament would have secured its pound of flesh without throwing the entire process into chaos.
As to whether this is a good way to select, or confirm, the European Commission, MEPs are almost unanimous in their belief that what they have done has brilliantly affirmed their part in the European democratic process. It is parliament's job to weed out weak commissioners, and that is what they have done.
Parliament's president, Josep Borrell, said that this was not a conflict between institutions but a normal part of politics. Parliament had carried out the role it was asked to play.
There may, however, be questions asked about the constitutional obligation for parliament to confirm the entire commission rather than individuals. There would certainly have been less of an upheaval if MEPs could have voted on each nominee individually.
Mr Buttiglione would have been voted out, but probably not the others - leaving Mr Barroso with the relatively simple task of finding one replacement, rather than reshuffling his entire team.