A referendum in Ireland saw 43 of 44 states voting in favour of the change, with just 38 per cent of those who voted, voting against it.

Australian Marriage Equality national director Rodney Croome said the decision would boost the equality campaign in Australia.

‘‘It will mean more Australian politicians will come on board, and it quashes the old myth that people of faith, particularly Catholics, oppose marriage equality,’’ Mr Croome said.

‘‘Ireland has traditionally been a socially conservative Catholic country, so for it to be so overwhelmingly in favour of this reform sends a clear message that it is time for the world to move forward on this issue.’’

Australian Christian Lobby managing director Lyle Shelton said the decision by Ireland was disappointing.

‘‘We have to consider the consequences of changing the definition of marriage for children. It means legislating for a family structure that requires children to miss out on a mother and a father and that is a big ethical issue,’’ Mr Shelton said.

‘‘If the gay lobby wants to keep going with their push ... they should try and convince the Australian population through a referendum.’’

Prime Minister Tony Abbott yesterday ruled out a referendum as the constitution states that marriage is governed by the Commonwealth parliament.

Northern Marriage Equality Group member Margaret Hughes said everyone who believed in marriage equality should now make their opinions heard.

‘‘It is important as Australian citizens that we acknowledge and celebrate any progressive move to achieving human rights,’’ Dr Hughes said.

‘‘Ireland’s decision illuminates Australia’s current legislation and highlights how excluding people here from the right and choice to marry serves to stigmatise, discriminate and oppress non-heterosexual people.’’