If so, it is odd that he is choosing to do it in a Newsnight interview which hardly anyone will watch rather than in a Personal Statement on the floor of the House of Commons, but his decision to speak out is significant none the less.
After all, it is not so very long ago that Clarke was still publicly maintaining that the Prime Minister would stay on until summer 2008 before standing down.
Perhaps the key to it is to remember that Charles Clarke was never really a fully paid-up Blairite. He was a Kinnockite, and Kinnock himself made clear as long ago as April 2004 his view that Blair probably ought to go soon after winning a third term.
June 27 Update: The story was not quite as billed. Despite the trenchant criticisms of Reid and the implied criticism of the reshuffle, Clarke apparently still wants Blair to stay on until 2008. Moral: Don't believe everything you read in the Sunday Telegraph and the Daily Mail...