The Garda Representative Association (GRA) is fully entitled to advocate a Yes vote in the same-sex marriage referendum, Fianna Fáil leader Micheál Martin has said.

Mr Martin was reacting to comments from former police ombudsman for Northern Ireland, Baroness Nuala O'Loan, who said she is appalled by the GRA's position.

Responding to an editorial in the GRA's Garda Review magazine in which members were urged to vote Yes, Baroness O'Loan said gardaí were not appointed to engage in political campaigns and must "remain apolitical during a referendum".

Speaking at the launch of Fianna Fáil’s same-sex referendum campaign launch, Mr Martin said: “I don’t agree with Nuala O’Loan’s position on that.

“One thing I have observed during the campaign is too much focus on petty and trivial issues and not enough focus on the arguments.

“The GRA is an association and (GRA general secretary) PJ Stone and others have had many views about different things and I think they are entitled to have a view on this.”

Mr Martin also said he will take part in any debates during the referendum campaign. Taoiseach Enda Kenny has been asked to take part in debates but has yet to commit to doing so.

“I think it is fair to say the Taoiseach has his own position on debates, not just in terms of marriage equality referendum,” Mr Martin said. “It is consistent.”