The First Minister of Northern Ireland will be getting a letter from the Trades Union Congress this week complaining about his wife’s claims that gay people can be turned straight.

TUC General Secretary Brendan Barber has written to Peter Robinson about Iris Robinson’s claims on BBC Radio Ulster last month.

The row overshadowed the Democratic Unionist Party leader’s first weeks in office.

“At a time when great progress is being made to bring about a more equal and tolerant society, one of the remaining challenges is the elimination of prejudice and hostility towards LGBT people,” said Mr Barber.

“At its worst, such prejudice finds its expression in violent attacks on people for no reason other than their sexual identity, and I find it particularly appalling that these public comments were made by a leading political figure on the occasion of another such crime.”

Mrs Robinson is MP and MLA for Strangford and chair of the Northern Ireland Assembly health committee.

Speaking on BBC Radio Ulster’s Nolan Show last month, she was asked to comment on a homophobic assault that took place in Newtownabbey.

Stephen Scott, 27, was attacked by a gang of youths and suffered head and leg injuries. The police are calling the incident homophobic in nature.

Mrs Robinson suggested that he should consider therapy to “cure” him of his homosexuality.

She condemned the attack on Mr Scott but added:

“I have a very lovely psychiatrist who works with me in my offices and his Christian background is that he tries to help homosexuals trying to turn away from what they are engaged in.

“And I have met people who have turned around to become heterosexual.”

She also agreed that homosexuality is “disgusting, loathsome, nauseating, wicked and vile.”

Police in Northern Ireland are investigating whether Mrs Robinson has committed any offence, such as incitement to hatred, after a string of complaints about her radio interview.

Sinn Fein, who are in coalition government with the DUP, have condemned her.

The TUC said it backs calls for a public statement by the Office of the First Minister and Deputy First Minister (OFMDFM) affirming the equal rights of LGBT citizens of Northern Ireland and condemning homophobic violence.

The TUC is also approaching the Equality Commission for Northern Ireland to investigate whether her statements made constitute incitement to homophobic hatred.

Mrs Robinson has subsequently claimed she is the victim of an anti-Christian witchunt, and later clarified her stance.

“Over the past few weeks, some people have attempted to suggest that I indicated that homosexuality is a mental-health issue, and they have twisted everything that was said on Stephen Nolan’s radio show,” she said in the Northern Ireland Assembly.

“I have got broad shoulders, and can take the brickbats that followed from that. However, nothing could be further from the truth. Homosexuality, like all sin, is an abomination.”