The proportion of people backing marriage equality in Northern Ireland dwarfs the level of support in the Republic, a campaigner suggested.
More than 400 same-sex couples have married in Ireland since the ban was lifted late last year. The country became the first in the world to vote for same-sex marriages in a referendum on this day last May.
Reports have suggested an increase in the number of LGBT young people who have come out in the Republic.
Amnesty International Northern Ireland director Patrick Corrigan said: “The 68% of people in Northern Ireland who have told opinion polls that they back marriage equality here dwarfs even the 62% of people who voted Yes in last year’s referendum in the Republic.
“People are impatient for change. They have just returned a majority of pro-equal marriage politicians to the Assembly and now expect them to deliver without further delay or the misuse of petitions of concern to veto the will of the people.”
Northern Ireland is the only part of the UK or Ireland where a ban on same-sex marriage remains in place.
Efforts to lift the prohibition have been defeated five times in the Stormont Assembly.
The DUP has argued that gay couples already have the ability to enter into civil partnerships and the appetite is not there for further change.
The historic law permitting the marriage ceremony in the Republic was enacted on November 16.
Grainne Healy, a co-founder of Yes Equality and Chair of Marriage Equality in the south, said: “It is a great joy to see the marriages that have taken place all around Ireland, with couples supported by their families, friends and communities in celebrating their love.
“Four hundred and 12 couples have already married since November last year. Hundreds more couples had their foreign marriages automatically recognised.
“We are delighted to share this day with those that helped and supported Yes Equality and look forward to many more happy days out for couples who can share in our joy.”