Fascinating to watch former mandarins causing mutiny among MPs, isn’t it? Labour backbenchers are threatening to defy Gordon Brown over demands from former top civil servant Sir Thomas Legg that they pay back some of their dodgy exes. Yet the last straw – particularly for the embattled PM – may come next week when Sir Christopher Kelly, chairman of the committee on standards in public life, publishes his report on MPs expenses. Whitehall insiders say Sir Christopher has had no love for Labour ever since he was pushed out of his top job at the health department in 2000. Despite a handsome pay off – there is speculation that his leaving package was worth at least £0.5m – Sir Christopher will have no reason to pull any punches.

I understand that he was asked to inquire into MPs’ exes on the recommendation of Sir Gus O’Donnell, the cabinet secretary. As young mandarins the two were at the Treasury together.