Irish voters are set to back the introduction of gay marriage by a margin of more than two-to-one next week and become the first country to approve the policy in a national plebiscite, a poll indicated on Saturday.
Long considered one of the most socially conservative countries in Western Europe, support for gay rights has surged in Ireland in recent decades as the power of the Catholic Church collapsed in the wake of a series of sex scandals.
The Irish Times poll of 1,200 voters showed 58 percent planned to vote in favour of the measure, which has the support of all the main political parties, compared to 25 percent against and 17 percent undecided.
The advantage of the Yes side has slipped, however, to 33 percentage points from 41 since the last poll two months ago.
Analysts have said the fall is nowhere near as sharp as the decline in support for divorce in a 1995 referendum, when that Yes campaign's 44 point advantage disappeared as conservative campaigners spoke out in the last weeks of campaign. The measure to allow divorce was approved by 50.3 percent.
Long a taboo in a country that only decriminalised homosexuality in 1993, gay rights have been championed by all the main political parties.
Prime Minister Enda Kenny was widely praised for appearing at a prominent gay bar last year at an event for gay members of his Fine Gael party.
The campaign has led to a number of high profile figures announcing publicly that they are gay, including the country's health minister and a prominent television journalist.
Campaigners against gay marriage have made some gains after warning that it might lead to an increase in adoptions and surrogacy births involving gay couples. Yes campaigners reject the claims.
Same-sex marriage was allowed for the first time in the United Kingdom last year, but it is still not permitted in Northern Ireland, where the Democratic Unionist Party of First Minister Peter Robinson has campaigned against it.
Irish voters go to the polls on Friday, with the results of the referendum expected the following day.