The deputy leader of France's Socialist Party, Laurent Fabius, has been sacked after he broke ranks with the party and campaigned against the EU constitution.
Laurent Fabius urged people to reject the EU constitution
France voted "No" to the constitution in a referendum last weekend, putting its future in doubt.
The main opposition Socialists voted on Saturday to oust former Prime Minister Mr Fabius from the party leadership.
Members also voted out Mr Fabius' supporters, electing a "homogeneous" leadership committee, a spokesman said.
At the instigation of Socialist leader Francois Hollande, the party voted for a new list of leaders that excluded Mr Fabius and several allies.
The decision came at a tense meeting in Paris, during which Mr Fabius and Mr Hollande were jeered by each other's supporters.
Although the party officially backed the constitution, it is estimated that some 58% of its supporters voted against.
Their decision is thought to have been crucial in the final result - in which about 55% of French voters rejected the treaty.
Many "yes" campaigners blamed Mr Fabius for the Socialist split.
Mr Fabius said afterwards: "I remain true to my stance."
In his speech to the party, he urged it to unite.
Francois Hollande failed to get his message to the French people
"A change of government is within reach," he said.
"A wrong direction could threaten it: a right direction could, by contrast, prepare it.
"That requires from all of us courage, a readiness to listen, wisdom and a real will for unity."
The issue of whether or not to support the constitution has caused deep divisions in the Socialist party.
Members are due to hold a convention in November to decide on their future direction.
But analysts say the split leaves the Socialists struggling to challenge President Jacques Chirac at a time when his popularity has plummeted and he has also been politically damaged by his failure to bring home a "Yes" vote.