Fine Gael has approved a motion calling on the Government to prioritise consideration of same-sex marriage.
The decision at today's Ard Fheis follows on from the introduction of civil partnership here last year.
The motion has been welcomed by the Gay and Lesbian Equality Network.
Chair Kieran Rose said the normalisation of civil partnership means Ireland is moving every closer to same-sex marriage.
Mr Rosa said: "All political parties have now taken policy positions supportive of civil marriage for same-sex couples. This is a very welcome development and builds on the widespread acceptance and support for the Civil Partnerships that are taking place all across the country."