The modifications were approved by a vote of 560 to 181. Three-fifths of the 577 deputies from the National Assembly and 330 senators had to vote in favor of the changes for them to become valid. 152 lawmakers abstained.

The vote paves the way for a ratification of the so-called Lisbon Treaty. The French National Assembly is expected to vote on Thursday to adopt the treaty itself, followed by the Senate and a final ratification by French President Nicolas Sarkozy.

No referendum this time

French and Dutch voters rejected a draft version of the European constitution earlier in 2005, provoking a long period of uncertainty over reform of the bloc's institutions.

The French president, however, campaigned strongly in favor of the new charter -- a watered-down version of the failed constitution -- and promised to have it passed by parliament, rather than run the risk of holding another referendum with an uncertain outcome.

For the treaty to be ratified, French lawmakers first had to agree on removing a now obsolete reference to the EU's thwarted constitutional treaty, which had been injected into the French constitution before the 2005 referendum.

But a recent survey showed that a significant majority of French adults wanted a referendum on the treaty.

Sovereignty of the people

Opposition Socialist deputies -- while approving of the Lisbon Treaty itself -- abstained from voting on the constitutional revision in protest of Sarkozy's decision not to open the vote to the people. Several hundred people protested in Versailles on Monday, demanding a new referendum.

"Nicolas Sarkozy thinks he is above the sovereignty of the people," warned Socialist deputy Henri Emmanuelli. "This is going to end badly,"

Sarkozy's ruling Union for a Popular Movement (UMP) party, which has a majority in both houses, unreservedly backed the treaty.

UMP spokesman Yves Jego said his party was "united, it is determined to ensure that Europe moves forwards and that this text comes into force as soon as possible."

After the big bang

The Lisbon Treaty was designed to streamline the EU's decision-making process following its "big bang" expansion of 2004, which welcomed 10 new member states into the 50-year-old organization. It is also set to improve the EU's global diplomatic clout by simplifying the way it relates with international partners.

The treaty must be ratified in all 27 EU member states before it can come into force in 2009, as planned.

Also on Monday, the Romanian parliament almost unanimously ratified the EU reform treaty on the Romanian news agency Mediafax reported. A total of 387 members of parliament and senators voted for the Lisbon treaty, while one voted against and one abstained.