Members of Parliament followed the vote with a standing ovation, the Italian news agency ANSA reported. Only members of the nationalist Northern League kept their seats.

But the vote, like others in most EU member states, could be meaningless. Irish voters rejected the treaty in a referendum, and the president of Poland has not yet signed the treaty more than three months after his parliament approved it.

''I am happy that the government, the majority and the opposition have expressed a common view on a crucial terrain for the future of the country,'' President Giorgio Napolitano said.

The treaty, negotiated while Portugal held the European presidency, is supposed to replace the documents that created the Common Market and other European organizations.