The proportion of people backing same-sex marriage in Northern Ireland dwarfs the level of support in the Republic, a campaigner has suggested.
More than 400 same-sex couples have wed 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 suggest a rise 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 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 is still 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 law allowing 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 Republic, 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."