Ireland, a traditionally Catholic nation, could become the first country in the world to vote for same-sex marriage in a historic referendum this week.
Voters on coming Friday will be asked whether or not 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 leading currently. Volunteers for and against gay marriage have been canvassing door to door in recent weeks and billboards have propped up, appealing for votes, as a colourful "Yes" bus makes its way around the country.
All the main political parties, including conservatives, are supporting the change, a seismic shift in a country where homosexuality was only decriminalised in 1993 and abortion is still illegal.
But a "Yes" victory is by no means certain and there is concern among proponents if the "Yes" supporters will come out and 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 in Ireland amid growing secularisation and after a wave of child sex abuse scandals that discredited the hierarchy.
"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 Saturday showed 70% support for the "Yes" side and 30% for the "No". The same pollsters in March had given the "Yes" side 78%.
There is a clear divide in the polls, with many older people and rural residents intending to vote "No".
Eighteen countries around the world have so far 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 previously been held in Croatia and Slovenia, and in both cases voters rejected legalising gay marriage. In Slovenia same-sex marriages were, however, legalised by parliament in March.
The constitutional referendum in Ireland would have to be followed by a specific legislation passed in parliament.