Ireland is set to enshrine the right to gay marriage.
Key campaign groups fighting the rights reform have conceded defeat, with results indicating a two to one majority of voters backing the constitutional change.
While no official confirmation is expected until late this afternoon, the country is on course to be the first nation to back the reform by a referendum.
Taoiseach Enda Kenny said there was a palpable movement of people wanting to get involved in the issue.
“I think from a young person’s perspective, particularly for those who travelled from wherever to wherever to put a simple mark on a paper, shows the value of the issue and the importance of politics,” he told RTE.
A high voter turnout was recorded in all regions, particularly in urban areas, with a huge youth vote and returning emigrants heavily influencing the ballot.
In Dublin the result was expected to be a landslide in favour of gay marriage while in many other parts of the country the constitutional amendment was expected to be passed by about two to one.
The Iona Institute, a Catholic-leaning think tank which spearheaded the No campaign, said it was a “handsome victory” for equal and gay rights activists.
Director David Quinn said: “It was always going to be an uphill battle. However, we helped to provide a voice to the hundreds of thousands of Irish people who did vote No.
“The fact that no political party supported them must be a concern from a democratic point of view.”
A formal declaration is expected closer to 5pm but indications even after only one hour of counting pointed to a resounding victory for the same-sex marriage campaign.
Senator David Norris, who fought from the 1970s to 1993 to have homosexuality decriminalised, said it was a wonderful result.
“I believe that by the end of today gay people will be equal in this country. I think it’s wonderful,” he said.
Results from the constituencies will be fed back to the count headquarters in Dublin Castle, where about 2,000 people are expected to gather in the upper courtyard to mark the day in colourful celebration.
It is only 22 years since Ireland decriminalised homosexuality.
Voters were asked one simple, specific question on whether to amend Article 41 of the 1937 Constitution by adding a new clause to a section titled The Family.
It asked them to support or reject a change to the 78-year-old document which reads: “Marriage may be contracted in accordance with law by two persons without distinction as to their sex.”
It does not suggest any change to the definition of the family or remove any outdated references in the section, including those that state a woman’s place is at home.
If passed, it would be the 34th amendment to the constitution but, regardless of the result, the campaign will rank with other hotly contested issues such as divorce and abortion.
Other countries have held referendums on the issue of gay marriage, including Croatia, Slovakia and Slovenia, but Ireland is now set to be the first to enshrine the reform in a constitution by popular vote.