The European Parliament has overwhelmingly approved the Lisbon Treaty.
The parliament in Strasbourg endorsed the treaty with 525 votes in favour, 115 against and 29 abstentions.
All 27 EU member states must individually ratify the text for it to come into effect, as planned, next year.
So far five - France, Hungary, Malta, Romania and Slovenia - have ratified the treaty.
Taoiseach Bertie Ahern told the Dáil this morning he hopes to finalise a date for the referendum on the treaty within the next few days.
He said it was the intention to hold the referendum at the end of May or early June.
He said he was anxious to give three months to the Referendum Commission to do its work.