John Larkin QC described it as an issue of “pure social policy” that should be left with the devolved administration.
His assessment came in proceedings brought by a gay couple whose marriage has no legal recognition in their native Northern Ireland.
The two men claim that being limited to civil partnership status within the region amounts to unlawful discrimination.
They are seeking a landmark declaration that their marriage remains fully constituted throughout the UK.
Granted anonymity in the case, the petitioner ‘X’ and his husband wed in London last year.
But under current laws they can only be classified as civil partners in Northern Ireland.
Legislation passed in the rest of the the UK and the Irish Republic allows same-sex couples to marry.
Last month Stormont voted in favour of the same change in law for the first time.
However, the Democratic Unionists blocked it by deploying a mechanism requiring the proposal to achieve a cross-community majority.
The petition, backed by gay rights group The Rainbow Project, has been taken against the Northern Ireland Assembly and the UK Government.
In first case of its kind counsel for X and his husband claimed their marriage has been “demeaned, devalued and undermined” by the situation.
The ban breaches rights to privacy and family life, religious freedom and entitlement to marry under the European Convention on Human Rights, it was contended.
X and his husband were able to wed in England following the introduction of the Marriage (Same-Sex Couples) Act 2013.
As the case resumed at the High Court today, Mr Justice O’Hara asked if the same same legal position should apply throughout the UK.
The Attorney General replied: “No, it’s a matter of pure social policy … being a transferred matter it’s for the devolved administration and the Executive.”
Mr Larkin insisted that the 2013 Act was clear, irrespective of how long a couple spend married in the rest of the UK.
He added: “It doesn’t matter, this is a general provision under which every same-sex marriage is for the purpose of the law in Northern Ireland treated as a civil partnership.”
The case continues.
Read more: http://www.newsletter.co.uk/news/northern-ireland-news/gay-marriage-is-a-matter-for-stormont-1-7094948#ixzz3tBSPIjAh