By Mark Devenport
Mrs Robinson obtained money from property developers to help her lover
The revelations about Iris Robinson's financial dealings with her young lover have come at a time when the Northern Ireland political process was already in serious difficulties.
Although her husband, First Minister Peter Robinson, categorically denies any wrongdoing, there is real concern that the need to deal with all the questions raised could distract him from his responsibilities and limit his ability to drive through any compromise.
The political problem in Northern Ireland focuses on the transfer of justice and policing.
Ever since Sinn Fein decided to back the police service they have been demanding that these powers should be devolved.
Republicans believe the DUP has broken the St Andrews agreement by delaying the transfer of the powers.
The DUP insists it never signed up to any timetable. Sinn Fein had said that if no date for the devolution of justice had been agreed by Christmas then the political process would be in "deep trouble".
Although republicans avoided spelling out precisely what this meant, the implication has been that the Stormont Assembly and Executive could fall.
Over the Christmas period, however, the political picture was complicated by two highly personal controversies.
First came the revelation that Sinn Fein leader Gerry Adams' brother Liam had been accused of sexually abusing his daughter, but had not appeared in court to answer charges.
Gerry Adams backed his niece, but questions were raised about his version of events - in particular his assertion that his brother had been dumped from Sinn Fein at a stage when archive photographs appeared to show he was still active in the party in the Dundalk area.
Sinn Fein has been hit by the allegations over Gerry Adams' brother Liam
Then came the start of the Robinson revelations; the announcement that Iris Robinson was standing down from public life because of her depression, the confirmation of her affair and a suicide attempt and then the BBC Spotlight allegations of illegality on her part.
If the negotiations between the DUP and Sinn Fein had been on the verge of a breakthrough, then republicans might have been expected to avoid too much adverse comment.
But on the evening the Spotlight programme went to air the two parties had what was by all accounts an extremely difficult meeting to discuss the devolution of justice.
In the run up to the meeting the DUP's chief whip at Stormont, Lord Morrow, said the transfer of the justice powers would not take place in the lifetime of the current Assembly, which is due to last until fresh elections in 2011.
Incensed by this, Sinn Fein made it clear that no progress was being made and called on the British and Irish governments to intervene.
In this context senior republicans felt no compunction in criticising Mr Robinson and expressing shock at the content of the BBC Spotlight programme.
Peter Robinson could face pressure to step aside from party members
DUP figures responded by referring to the questions posed in relation to Gerry Adams' family difficulties.
The first and deputy first ministers were as one in condemning the latest dissident republican attack on a police officer in Randalstown, but their parties are finding it difficult to agree on anything else.
Regardless of the state of the justice negotiations, other Northern Ireland politicians feel both Iris and Peter Robinson have serious questions to answer.
They have demanded Mrs Robinson's immediate resignation as an MP and called for further inquiries into Mr Robinson's handling of the matter.
The British and Irish governments had been hoping that the DUP leader would be able to persuade those of his party colleagues most dubious about any early transfer of justice powers that real movement is needed to break the deadlock at Stormont.
But officials are now anxious that his reliance on the support of his colleagues may mean he no longer has the authority to broker a compromise. If so, there is no way of avoiding Sinn Fein's "deep trouble".
Peter Robinson intends to fight on as party leader. So far the only senior DUP figure to speak in public, Stormont Environment Minister Edwin Poots, has defended Mr Robinson.
But off the record some DUP figures have expressed shock and expressed the view that Mr Robinson's colleagues should tell him it would be best if he stood aside in the run up to the forthcoming Westminster election.
It may not come to that, but either way it's hard to see the British and Irish governments brokering a compromise any time soon.