Which senior cabinet minister thinks he’s been over-promoted?

Adam Boulton has a great little scoop over at his blog, one senior member of the cabinet has been telling colleagues that he has been over promoted but that he intends “to enjoy it while it lasts”. Now, it is a man which rules out Jacqui Smith, Harriet Harman, Yvette Cooper, Ruth Kelly and Hazel Blears. It is unlikely to be Jack Straw or Geoff Hoon who have previously held higher office than their current rank. That it is a senior cabinet minister seems to rule out Douglas Alexander, Andy Burnham, Ed Miliband, Shaun Woodward and Paul Murphy. Several others are unlikely to be self-aware enough to make such a comment. So, who could it be?