PARIS -- France Prime Minister Lionel Jospin received a rubber-stamp endorsement of his presidential bid from his Socialist Party on Sunday, when it met in an extraordinary Congress in Paris, AFP reported.

The party vote, in which Jospin was the only candidate, made him the Socialists' official contender for April-May elections against incumbent center-right President Jacques Chirac.

The prime minister announced last Wednesday that he was running against Chirac in a repeat of the competition in 1995 that saw Chirac become head of state by a slender margin.

French voter intention polls put the two men neck-and-neck and dismiss the chances of the 17 other candidates who have put their names forward.

The presidential elections are to be held April 21 and May 5, and are to be followed weeks later by June legislative elections.

The 1,000 Socialist Party members at the Sunday Congress had gathered in front of a banner over a podium reading "presiding differently".

As Jospin made his way across the room at the opening of the Congress, many yelled out "Lionel for President" and "We're Going to Win" while a campaign melody played.

"I can't guarantee success. There is an incumbent president. I am only the challenger," Jospin told the room.

But, he added, "I can guarantee one thing: I am not, as in 1995, a bystander. I commit myself to this campaign, in front of all French people, with the aim of winning."

Chirac did not deserve reelection because he had been both "unfaithful" to his mandate and "passive", he said.