Voters in the Catholic nation will be asked on Friday whether to add an article to the Irish constitution saying: “Marriage may be contracted in accordance with law by two persons without distinction as to their sex.”

The latest polls show the “Yes” side in the lead. Volunteers for and against gay marriage have been canvassing door-to-door and billboards have ­appeared appealing for votes, as a colourful “Yes” bus makes its way around the country.

All the main political parties, including conservatives, support the change — a seismic shift in a country where homosexuality was decriminalised only in 1993 and abortion is still illegal.

A “Yes” victory is by no means certain and there is concern among proponents about whether “Yes” supporters will come out to cast their ballots.

“We will ensure that people will be treated equally, no matter who they love,” Prime Minister Enda Kenny has said.

The move is opposed by the Catholic Church, whose influence has waned amid growing secularisation and after a wave of child sex abuse scandals.

“Marriage should be reserved for the unique and complementary relationship between a woman and a man from which the generation and upbringing of children is uniquely possible,” the Irish Catholic Bishops’ Conference said in a statement.

An Irish Times/Ipsos MRBI poll published over the weekend showed 70  per cent support for the “Yes” side and 30 per cent for the “No”.

Eighteen countries have legalised gay marriage or are about to do so, including 13 in ­Europe. Across the border in Northern Ireland, gay marriage is banned even though it is legal in the rest of Britain.

Referendums have been held in Croatia and Slovenia, and in both cases ­voters rejected legalising gay marriage. In Slovenia same-sex marri­ages were legalised by parliament in March.

The constitutional referendum in Ireland would have to be followed by specific legislation passed in parliament.

The central “No” argument is that the constitutional amendment would undermine the traditional definition of marriage and would facilitate laws allowing gay couples to adopt or have surrogate children. But officials have pointed out that same-sex couples can already adopt children under the current legislation.

The “Yes” side has been backed by sports, music and film stars including Hollywood A-lister Colin Farrell. U2 frontman Bono was quoted by the Irish Times as saying: “Trying to co-opt the word marriage is like trying to co-opt the word love.”

AFP