Lawmakers meeting in special session have voted in favor of a sweeping revision of France's constitution _ but by a one-vote margin that highlights the controversy behind the vote.

The changes give parliament greater power but also add privilege to the presidency.

The reform was a political hot potato for President Nicolas Sarkozy, but the thin win _ 539 votes for and 357 against _ has saved him from humiliation. That is one vote more than the 538 needed to pass the changes.

The vote was held Monday by both houses of parliament meeting at the Chateau of Versailles.

Sarkozy's conservative party pressed for the reform right up until the vote.