THE Catholic church has changed its views on mixed marriages and may do so about gay marriage in the future, Tanaiste Joan Burton has suggested.
Ms Burton cited the example of "mixed marriages" between a Catholic and a Protestant, which were carried out in the early morning at side altars.
She said that this was common up to 50 years ago but then the church changed its view.
The Labour leader was answering questions about comments made by the leader of the Catholic Church in Ireland, the Archbishop of Armagh Dr Eamon Martin.
He said the church would have to consider continuing to perform the civil part of wedding ceremonies if the voters endorse same-sex marriage in the referendum on May 22.
But Ms Burton said the forthcoming referendum is about changing civil marriage - and has no impact on religious marriage.
"We have had these debates over a long period of time," she said. "There was a time, when in the church's wisdom, if for instance a Catholic got married to a Protestant, they had to get married very early in the morning and generally not in the main body of the church.
"That was practiced 50 years ago, that was regarded as 100pc not changeable.
"The church like every organisation reflects the changes in society. But what the church decides is entirely a matter for the church," Ms Burton said.
Launching his party's campaign for a 'Yes' vote on May 22, the Green Party leader Eamon Ryan said that "as a proud Catholic" he was voting 'Yes' to gay marriage.
"I, as a Catholic, will vote 'Yes' on the basis of my informed conscience," Mr Ryan said after welcoming many of Dr Martin's remarks on the need for debate.
Asked about the comments by Dr Martin on ending civil marriage in church, Mr Ryan cited Pope Francis's statements that the church was essentially made up of the people. Mr Ryan said that over time the church can change its stance in line with the views of its followers.
Ms Burton, who as Social Protection Minister is responsible for marriage registration services, said whatever the Catholic Church wishes to do in relation to marriage ceremonies is a matter for the church.
She said the forthcoming referendum was about civil marriage and must not be mixed up with other issues.
The Archbishop was speaking on RTE's Morning Ireland programme when he said the question of the church continuing with civil marriage in the event of a 'Yes' outcome clearly must be considered.
"We would have to look at legislation to see is it possible for us to continue to stand over our ministers being involved in civil ceremonies" he said.
Dr Martin said the issue would have to be fully discussed by the conference of bishops and may not arise at all if the referendum is rejected.
He also raised other issues which need discussion, including teaching on marriage and sex education in schools if the Yes side wins.
Labour's referendum director, Alex White, said these matters can be dealt with.