UPDATE: A No. 10 source spins to The Standard: “This is not a sudden thing at all but something that has been planned and talked about for quite a long time. This was a retirement not a resignation. At 66 he wanted to pursue charitable and business work. Lord Sainsbury has other things he would like to do.”
Wonder if he will call in his loans to the Labour party? (The ones he can remember.)
UPDATE II: BBC catches up with Guido 25 minutes later… no word from Nick Robinson yet..