The Seanad has given tacit approval to the Government's plan to stage a second referendum on the Nice Treaty for EU enlargement, clearing the way for a date to be set.
The Seanad agreed the enabling legislation for the referendum without a vote, sending it to President Mary McAleese for her signature, which is a formality, officials said.
The Government is then free to set a date for the second referendum on the treaty, which voters rejected last year in a surprise result.
The Dáil approved the legislation on Wednesday.
The second referendum, which has generated heated debate, is expected to be held sometime in late October after a required 30-day waiting period.
The Taoiseach Bertie Ahern has been playing his cards close to his chest, refusing to divulge an exact date.
All the government and major opposition parties support the Nice Treaty, which reforms the internal workings of the EU to admit the new member states.
But a loose coalition of opponents, ranging from the Green Party and Sinn Féin, to eurosceptics and pacifists, is fired up to defeat the treaty a second time.