A special congress of the French parliament meeting at Versailles has taken a significant step towards ratifying the EU's new reform treaty.
Mr Sarkozy wants to avoid another referendum on the treaty
More than 900 MPs and senators voted on Monday to delete a reference in the French constitution to the ill-fated EU constitutional treaty.
A "No" vote in France and the Netherlands in 2005 sounded the death knell for the EU constitution.
France is due to complete ratification of the new treaty this week.
Although most Socialists abstained, 560 MPs and senators voted in favour of the amendment and another 181 opposed it, easily passing the necessary 60% margin required.
The treaty - which was agreed in Lisbon last year - has the support of the ruling UMP party of President Nicolas Sarkozy.
Although opinion polls in France suggest a majority of voters would prefer to have another referendum, President Sarkozy has called for a speedy ratification before France takes on the EU presidency in July.
The president chose the parliamentary path for ratification because he did not want the risk of a second defeat in a popular referendum, Paris reporter Hugh Schofield says.
A final vote is due to take place in the National Assembly on Wednesday and the Senate on Thursday.
On Monday, the Romanian parliament overwhelmingly ratified the treaty. Hungary, Malta and Slovenia have already done so and Ireland is the only EU member state due to hold a referendum on it.