If David Cameron is anything like Tony Blair, he will be following the Labour leadership elections closely. There are many important people in the life of a Prime Minister, and in our system in particular, the Leader of the Opposition is one of the most important.

TB used to think a lot about his opponents, and used to fret endlessly when there was a contest on, or when there were doubts as to whether the incumbent would survive. As was clear from Prelude to Power, he went through a phase of worrying that Michael Heseltine, or even Michael Portillo, would take over from John Major, and that Labour’s prospects pre-1997 would suffer as a result.

Future volumes will reveal similar TB anxieties whenever, partly as a result of our election wins, new Tory leaders were being elected. He faced five in all – Major, William Hague, Michael Howard, Iain Duncan-Smith and David Cameron. He found  Tory leadership elections very difficult, because there was not much he could do to influence them directly and yet he knew the outcome would be significant for him and his role.

He felt all had strengths and weaknesses but I think it is fair to say he felt the Tories made the best choice in all of the contests up until the last one – the best choice for Labour that is. He would have feared Heseltine more than Major; Hague wasn’t ready and in any event lacked real judgement; Howard was unpleasant and unpopular, and an opportunist, a pretty lethal combination; Duncan-Smith lacked weight and was too much in hock to his Party’s right; Cameron, TB felt, was the right choice against David Davis, as he offered at least the possibility of real change.

All this is by way of preamble to commenting on the story that David Cameron has reportedly stated that Ed Miliband is the opponent he wants, and David Miliband the one he fears.

Now who knows, given what else they get up to, that this isn’t some sophisticated piece of spinning by Cameron’s media manipulators? I somehow think, however, that it accurately reflects his opinion: that Ed would take Labour significantly leftwards and leave even more of the centre ground open to the Tories, and that David has the necessary strength both to take him on in Parliament – hugely important – and provide fresh energy and direction for Labour in the country.

It would be easy to dismiss the view of the man who would be the new Labour leader’s direct opponent. However, if my experience of TB is anything to go by, it might also be an idea to listen to it. If Tory members had known what we were thinking as they elected one failed leader after another, they might not have done it quite so often.