"There is a very serious problem and we can't really say it's business as usual," European Commission chief José Manuel Barroso admitted today, a day after French voters rejected the constitution.
But "there is no plan B. It's not reasonable to even think of a renegotiation," Barroso told French news channel LCI, according to Agence France-Presse.
Luxembourg Prime Minister Jean-Claude Juncker, whose country holds the EU rotating presidency, said: "The process of ratification must continue in the other countries."
French President Jacques Chirac, meanwhile, moved forward with a widely expected government shakeup.
He was scheduled to speak on radio and television Tuesday night, the Elysee Palace said.
German Chancellor Gerhard Schröder expressed regret at the outcome but said it did not mean the death of the charter.
France was the 10th EU country to vote on the constitution and only the first to reject the text, which is designed to streamline the way the bloc is run and establish deeper political union among the 25 member states.
The constitution faces a vote Wednesday in the Netherlands, where polls show it with minority support.