Nobody watching the beginning of the emergency debate today in Parliament on the PBR could have failed to notice the look of abject horror and disgust on the face of the Chancellor as George Osborne got up to speak. He looked as though he strongly resented the defence he was being forced to give on behalf of his leader - who, after all, is directly and personally to blame for the situation the country finds itself in.
His speech - although faltering - appeared measured and reasonable. He remained generous in his attempts to give way to interventions. He appeared almost as disgusted as his listeners in delivering the carefully agreed lines about the signed copy of the secret tax increase and how - in reality - the Minister could not have signed it because he didn't know it existed.
The reason that Darling loses so conspicuously to Osborne is that Darling has a closer relationship to the truth than his boss - who is prepared to lie blatantly and loudly if he thinks it will get him out of trouble. When Darling lies it shows upon his face.
Which - together with the obvious argument between Brown and the Treasury last week - leads me to wonder whether just as Margaret Thatchers Parliamentary downfall was brought about by Geoffrey Howe - a man whose debating was famously compared to that of a "dead sheep", Brown's might end up being at the hands of a timid - but fundamentally decent - Old Badger.