By my reckoning, yesterday will be remembered as perhaps the most difficult of Sir Keir Starmer's premiership yet, with even close allies telling me they are not sure where it will end. His admission at Prime Minister's Questions that he knew of the friendship between Peter Mandelson and Jeffrey Epstein when he appointed him as US ambassador hardened the sentiment of many a Labour MP who was willing to give him the benefit of the doubt. Insiders tell me that changed when Starmer told the