Weber Shandwick NI managing director Conall McDevitt said: ‘It has been a PR disaster. Mr Robinson's pre-emptive interview early last week failed as an attempt to divert attention from the disclosures. It worked for 24 hours but now his position is becoming untenable.
'He has lost all political authority and there seems to be very little support either inside or outside the Assembly.'
Robinson continues to hit the headlines today after it emerged last week that his wife Iris had an affair with a teenager. Subsequent revelations include claims that Mrs Robinson secured money from two property developers, which she gave to her lover.
Allegations that Robinson knew about the financial matters have prompted calls for him to quit his post as leader of the Democratic Unionist Party. He is expected to address senior party figures today about his wife's affair and her financial dealings.
McDevitt added: ‘The story is getting legs because it is a mind-blowing cocktail of sex, money and power. If I were Peter Robinson I would be thinking very seriously about whether my position is tenable.'
Statekholder Communications MD Brendan Mulgrew said: 'It was a tremendously difficult situation to handle in PR terms and it has not been handled well at all. When Peter Robinson gave his pre emptive interview on Wednesday some people thought it was a PR masterstroke. Given what followed on Spotlight it was in fact clearly an attempt to equalise before the other team scored. It was too managed, too forced, and too staged. Since then Robinson has cut a lonely figure, with few colleagues offering support.'
He added: 'If Robinson has the stomach to go on, he needs to stress the paucity of the alternatives to his leadership, and he must then demand a totally united front when he addresses the media. He must be surrounded by senior party colleagues if he wants to show a united DUP message.'
The BBC's Panorama is planning to run another programme on the Robinsons tonight.