The Government is going to call for Yes vote to gay marriage, a spokesman said.
The announcement means Fine Gael will be supporting same-sex marriage.
The coalition has confirmed the gay marriage referendum will take place before the middle of 2015.
"My understanding is Government will actively support it," spokesman says
Taoiseach Enda Kenny told the Cabinet he is in favour of gay marriage, Independent.ie has learned.
Mr Kenny had assiduously avoided expressing his view on the issue up until now.
The Government decided today to hold a referendum on gay marriage in 2015.
The Taoiseach told his Cabinet colleagues he too was now in favour of gay marriage.
Previous to today’s events, Mr Kenny had repeatedly failed to say where he stood on the question of gay marriage and had studiously avoided questions on the issue.
Earlier, the Cabinet decided to approve the holding of the gay marriage referendum, on foot of a recommendation of the Constitutional think tank.
Tanaiste Eamon Gilmore was seeking the gay marriage referendum be held in Autumn 2014 or Spring 2015.
Mr Gilmore said last week he wants adoption and guardianship laws brought in before any referendum takes place.
The issue arises after the Convention on the Constitution recommended extending marriage to same-sex couples.
And the coalition has four months to respond with the deadline being next week.