The French prime minister, Jean-Pierre Raffarin, has said there will not be a second referendum if France says "No" to the Constitution on May 29.
Another referendum is "not a perspective that France could accept", he told TV channel BBC World on Tuesday as cited by EU Observer.
"France will express itself, it will express itself once, there will be no second round or second chance. Once she has spoken, her message is clear", said Mr Raffarin.
But "in France's democracy, there is no such thing as a 'little yes' and a 'little no'," Mr Raffarin said.
"What matters is victory. Be it 'yes' or 'no', the result cannot be contested. That's democracy", he added.
Polls show that a majority of French citizens will reject the EU Constitution. A poll published in Tuesday's (25 may) Le Figaro put the no camp at 53 per cent.