The Taoiseach, Enda Kenny, said he will outline his position on gay marriage on Tuesday, when the Cabinet will decide the date for a referendum on the issue.
Labour is pushing for a referendum in the lifetime of the coalition, and it is thought it could take place either late next year or early in 2015.
It is understood Fine Gael will agree to a referendum, but the party has no official position on the issue, and the Taoiseach himself has so far refused to show his hand.
The Government is forced to consider the issue in order to meet the deadline for responding to recommendations from the Constitutional Convention, which sent its report to the Oireachtas in recent months.
When asked when he would clarify his position, Mr Kenny told reporters at a Fine Gael dinner in Dublin last night that he planned to do so on Tuesday.