Prominent gay human rights activist Peter Tatchell has called on the next Stormont Assembly to overturn Northern Ireland’s ban on same sex marriage.
The Love Equality campaign is lobbying candidates ahead of the May 5 poll.
Same sex marriage has been rejected five times by members of the devolved legislature.
Mr Tatchell said: “Marriage equality is now an election issue.”
Last summer about 20,000 campaigners marched through Belfast city centre demanding a change in the law.
Following the Yes vote in last May’s referendum on marriage equality in the Irish Republic, Northern Ireland is the only part of the UK or Ireland where civil marriage is denied to same-sex couples.
However, the largest party, the Democratic Unionists, argued that the issue did not command sufficient cross-community support.
Although the majority of Assembly members voted in favour of introducing gay marriage when it was debated for a fifth time last year, the proposal fell because unionists who opposed the move deployed a controversial voting mechanism to veto it.
The DUP has in the past been heavily influenced by socially conservative evangelical Christians including its founder the Rev Ian Paisley but has been under the leadership of modernisers for some years.
Mr Tatchell added: “Successive DUP health ministers have maintained a lifetime ban on gay and bisexual blood donors; acting against the medical advice that led to the easing of the ban in England, Wales and Scotland.
“For many years the DUP opposed the right of same-sex couples to adopt children, the introduction of civil partnerships and the holding of LGBT Pride parades in cities like Belfast.
“It is currently the main obstacle to the legalisation of same-sex marriage.”
John O’Doherty, head of the Rainbow Project gay rights organisation in Belfast, said since the Yes vote in the Republic marriage equality has become a major political issue for many voters - straight and gay - in Northern Ireland.
“Last summer, 20,000 people marched through Belfast demanding marriage equality - one of the biggest political demonstrations Northern Ireland has seen in years. Those people haven’t gone away.
“On May 5th they will be looking for candidates who promise to deliver equality for everyone. Marriage equality is now an election issue.”