This is on you, Mrs Robinson

Northern Ireland leader Peter Robinson stepped aside as first minister yesterday for six weeks to clear his name amid a scandal linked to his wife's affair with a teenager.

The move - which comes after days of sustained pressure on Robinson to resign after news of the scandal broke last week - is likely to add to strains in the already tense power-sharing government.

Enterprise minister Arlene Foster has been asked to take on the functions of first minister during his absence, Northern Ireland Assembly speaker William Hay told MPs.

Robinson's wife Iris, 60, also a top politician, last week admitted having an affair with a 19-year-old and securing £50000 (R593123) from two wealthy developers to help him set up a cafe in Belfast.

Peter Robinson, 60, leader of the Democratic Unionist Party, has denied any knowledge of the deal, which he would have had to report to parliamentary authorities.

Robinson bowed to pressure yesterday after the DUP's power-sharing partner Sinn Fein tabled an emergency motion calling for him to explain himself.

Until her bombshell admission of an extra-marital affair and financial entanglement with the baby-faced lover last week, Iris Robinson had been the female contingent of Northern Ireland's premier power couple.

The flamboyant redhead was widely seen as the ''power behind the throne" in the rise to the top of her husband of 40 years - who took over the reins of power from Protestant veteran leader Ian Paisley in July 2008.

But like her husband, a trained lawyer and astute political strategist, Iris Robinson had a thriving career in her own right in the mainstream Democratic Unionist Party.

She was elected councillor for the DUP in 1989, proceeded to become Northern Ireland's first female borough mayor and won a seat in the Northern Ireland Assembly [devolved parliament] and the House of Commons in London in 1998.

Ten years later, Iris Robinson started a sexual relationship with Kirk McCambley, son of a close friend who had died.

Robinson, who is now receiving psychiatric treatment, tried to take her own life when she admitted her affair to him in March last year, her husband said.

She had stirred controversy before in deeply conservative and religious Northern Ireland when, in 2008, she described homosexuality as an ''abomination".

Political analysts have pointed out, however, that much more than a spicy extra-marital affair lies behind the demise of Northern Ireland's leading husband and wife team.

''The brutal fact is that we were heading for a dangerous political crisis in Northern Ireland even before the Robinson revelations," Paul Bew, professor of Irish politics at Queen's University, Belfast, wrote in London's The Times yesterday.

Opposition and suspicion towards the power-sharing arrangement between the Protestant DUP and the Republican-Catholic Sinn Fein Party, led by Gerry Adams, remains deep-seated in a province whose history of violence is rooted in religious rivalry.

The lingering doubts and mutual lack of trust in the process of reconciliation has recently been exemplified by the ongoing difficulties over the transfer of police and judicial powers to the Northern Ireland Assembly from the Westminster parliament in London.

Robinson, faced with steep opposition from within his party against the power transfer - the final step in the full implementation of the peace accord - has refused to agree to the transfer during months of wrangling.