The Northern Ireland Assembly has rejected a motion calling for same-sex marriage to be introduced.

It is the third time the assembly has voted down a same-sex marriage motion in 18 months, with stiff opposition from DUP and some UUP members.

The motion had been tabled by six MLAs, from the Alliance, Sinn Féin and Green parties, but its passage was deemed unlikely after DUP tabled a petition of concern, hindering cross-party efforts to pass it.

MLAs from the Social Democratic, NI21 and Labour parties also backed the motion, while the sole UKIP and Traditional Unionist Voice MLAs voted against.

Two Alliance MLAs, Judith Cochrane and Trevor Lunn,voted against the motion despite their party supporting it.

DUP MLA Mervyn Storey told the Belfast Telegraph: “The re-definition of marriage would represent a change of monumental significance. It must not happen in Northern Ireland.”

Patrick Corrigan, director of Amnesty International, said: “Politicians in Northern Ireland who continue to block marriage rights for same-sex couples are like latter-day King Canutes, trying in vain to hold back the tide of equality.

“States may not discriminate with regards to the right to marry and found a family, on the basis of sexual orientation or gender identity.

“That obligation is clear in international law.”

Callum Webster, a spokesman for The Christian Institute, said: “The people of Northern Ireland are clearly opposed to redefining marriage and it’s only a political elite who are trying to force the change on the Province.”

“Just because politicians at Westminster have ridden roughshod over the opinions of hundreds of thousands of ordinary citizens and redefined marriage, doesn’t mean Northern Ireland needs to follow suit.”

Amnesty International has said equal marriage in Northern Ireland could eventually be secured in the courts – in order to bypass the DUP’s opposition.