Homophobic MP Iris Robinson allegedly solicited £50,000 from two property developers to help her 19-year-old lover set up a business.

The Northern Ireland MP broke parliamentary rules by not declaring her interest in the business, despite sitting on the council which awarded the money to Kirk McCambley, it was claimed.

According to a BBC Spotlight programme broadcast last night, Mrs Robinson, 60, also demanded a £5,000 kickback from Mr McCambley for helping arrange the transaction.

Today, her husband Peter Robinson, who is Northern Ireland’s first minister, denied he had done anything wrong.

It was claimed he knew about the solicitation and had demanded the return of the money, but had not alerted parliamentary authorities.

Mr McCambley runs the the Lock Keepers Inn, a cafe in Lagan Valley regional park in south Belfast. The building in which the cafe is situated was built by Castlereagh Borough Council, on which Mrs Robinson sits as a councillor.

In a news item on the council’s website in September, Mr McCambley said: “When we first told friends about the opportunity, they said we were mad but the National Lottery and the council could see the potential prosperity of the park.”

In a statement on Wednesday which mentioned a suicide attempt when her husband found out about the affair, Mrs Robinson said she had encouraged friends to give her teenage lover money for a financial venture.

Mr McCambley and a former advisor to Mrs Robinson, Selwyn Black, were interviewed in the BBC programme.

Mr Black mentioned a string of text messages sent to him from Mrs Robinson. After the affair ended, she allegedly wanted half the money to be funnelled through her local church, where her sister is a pastor and the other half to be sent in a cheque to her. It was alleged she regarded the money as her own.

The affair took place in March 2008, when Mrs Robinson was 59 and Mr McCambley was 19.

The property directors who stumped up the £50,000 were Fred Fraser, now deceased, and Ken Campbell. Campbell was a family friend and it is unclear whether she used her position as an MP to persuade him to make the donation.

In the programme, Mr McCambley revealed he had known Mrs Robinson since the age of nine.

He said: “I worked in the butchers since I was nine and I always seen her coming in and out. I knew her from a very early age through the butchers and through my dad.

“She looked out for me and made sure I was OK and obviously anyone who has lost a parent knows it is an incredibly hard time and she was there to help.”

Commentators have suggested that Mr Robinson’s position as first minister may become untenable.

Last night, he denied allegations of wrongdoing.

He said: “I completely reject BBC Spotlight’s attempt to implicate me by insinuation and innuendo.

“I am even more appalled by the inclusion on that programme of comments and conclusions made without any supporting facts – indeed with facts in the programme which support a contrary position.

“While I have learned from Spotlight for the first time some alleged aspects of my wife’s affair and her financial arrangements, I will be resolutely defending attacks on my character and contesting any allegations of wrongdoing.”

He is expected to make a further statement today.

This morning, The Alliance Party and Ulster Unionist Party called for her to step down as Strangford MP and Northern Ireland Assembly member immediately.

Mrs Robinson is understood to be too unwell to comment. She announced in late December she would be stepping down from politics due to mental ill health.