Bishop of Kilmore Leo O'Reilly has today questioned the length of time given to the Constitutional Convention to consider same-sex marriage.

The 100-member convention is hearing from the views of religious organisations and human rights groups on the matter this afternoon at a meeting in Dublin.

They will vote tomorrow on whether to recommend to the Oireachtas that the issue of same-sex marriage should be put before the people in a referendum.

Addressing the convention on behalf of the Irish Catholic Bishops Conference, Bishop Leo O'Reilly said that there a number of profound and fundamental questions to be decided upon.

"You've been asked to decide if the differences between women and men really matter anymore, especially in their role as mothers and fathers," he said.

"You've been asked to consider if, for the first time, for the first generation in human history, the roles of mother and father are to be consigned to history and be considered irrelevent in the bringing up of children."