A motion to set up a new investigation into evidence around the cause of the Stardust fire has been passed by 94 votes to 50.
It follows yesterday's agreement between Fine Gael and the Independent Alliance, to ask a legal figure to examine new claims by the victims' families.
A Commission of Investigation will be set up if the new probe finds that it is justified.
Sinn Féin and a number of other TDs voted against the motion, arguing that a full Commission of Investigation should be set up immediately.
The Irish Examiner reported this week that Super Junior Minister Finian McGrath has threatened to resign if an inquiry does not go ahead.
Forty-eight young people died in the 1981 Stardust nightclub fire in Artane in Dublin. A previous tribunal suggested the fire was "probably" caused deliberately.