The Northern Ireland Assembly will debate equal marriage on 29 April in a motion filed by several MLAs (Members of the Legislative Assembly).
Northern Ireland is the only remaining UK nation where same-sex marriage has not been legalised.
The motion states: “That this Assembly notes that other jurisdictions on these islands have moved forward with equal marriage rights for same-sex couples; believes that all couples, regardless of gender or sexual orientation, should have the same legal entitlement to marry”.
They have the most MLAs of any party in the Assembly.
Sinn Fein, the Social Democratic and Labour Party (SDLP), the Alliance Party and the Greens all support equal marriage.
The DUP has continually resisted supporting LGBT equality across the board. First Minister Peter Robinson and Health Minister Edwin Poots have refused to lift Northern Ireland’s lifetime ban on gay and bisexual men giving blood.
Demonstrations by equal marriage campaigners took place in Northern Ireland last month on the eve of the first same-sex marriages in England and Wales in order to highlight the equality gap in the province.
Same-sex marriages conducted in England and Wales are currently only recognised as civil partnerships.
Amnesty International’s programme director in Northern Ireland, Patrick Corrigan, believes equal marriage could eventually be secured in the courts – if the DUP continues to obstruct the measure.
He said: “There could be a straightforward legal challenge on the basis of inferior treatment of same-sex couples in Northern Ireland with regards to the right to marry and found a family.”