The Italian parliament ratified the European Union's Lisbon Treaty on Thursday.
All MPs and ministers rose to applaud the unanimous vote except the Northern League who did not budge.
Italian President Giorgio Napolitano said the vote reflected ''renewed prestige for the European role of our country''.
''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,'' he said.
He voiced the hope that the EU's ratification process would be completed before next June's European Parliament elections.
Most EU states are in the process of ratifying the Treaty, which aims to streamline the bloc's institutions after expansion.
It must be ratified by all 27 member states before taking effect.
But Ireland rejected it in a referendum in early June, a move plunging the 27-member bloc into crisis over its integration process.
Poland's president is also dragging his feet over signing the Treaty which was approved by his country's parliament in April.
