Amnesty International has predicted that a gay couple will challenge the ban on same-sex marriage in Northern Ireland through the courts in 2015.

On the same day Scotland saw its first same-sex marriage, Amnesty’s new year message in Northern Ireland welcomed any legal case against the ban in the region.

Patrick Corrigan, Amnesty’s Northern Ireland programme director, said: “We look forward to seeing that discrimination being challenged in the Northern Ireland courts during 2015.

“We have long predicted that, should Northern Ireland’s politicians fail in their duty to end such discrimination, then gay people will resort to the legal system to have their human rights as equal citizens vindicated. We expect that to happen in 2015.”

Corrigan added: “That obligation is clear in international law. This means that marriage should be available to same-sex couples in Northern Ireland, just as it is now in Scotland, England and Wales.

“There is still a chance for Northern Ireland’s politicians to do the right thing in 2015. However, if they continue to abdicate their responsibilities, judges instead will be asked to uphold the right of all our citizens not to face discrimination.”

The Irish Republic is to hold a referendum this spring on legalising gay marriage in the state. If, as successive opinion polls suggest, the republic backs full equality for same-sex marriage, it will leave Northern Ireland as the only part of these islands where gay marriage is not given equal status.

Meanwhile, the honours list for Northern Ireland included an MBE for a Ballymena councillor who stated that hurricane Katrina was God’s revenge for an annual gay event called the Southern Decadence festival.

On the 2005 disaster which killed 1,300 people and left tens of thousands homeless, Democratic Unionist councillor Maurice Mills said: “The media failed to report that the hurricane occurred just two days prior to the annual homosexual event called the Southern Decadence festival which the previous year had attracted an estimated 125,000 people,” said Mills.

“Surely this is a warning to nations where such wickedness is increasingly promoted and practised.”

Mills also blamed the spread of Aids in Africa on gay people. “This abominable and filthy practice of sodomy has resulted in the great continent of Africa being riddled with Aids,” he said.

The gay rights organisation the Rainbow Project demanded that his party reject Mills’s comments but the DUP declined to do so. The DUP councillor has never retracted his remarks.