Andrew Rawnsley: Boris Johnson reminds Tories of what David Cameron has lost - Number 10 says it is relaxed about the mayor's speech at conference. It is as relaxed as a cat on a hot tin roof

Those of them who do admit that Boris is a problem say that at least: "There are worse rivals you could have." There's some truth in that. The mayor is not a member of the cabinet. Being detached from the government, and all the unpopular and misconceived decisions that it has made, is part of the explanation for why he is much the most popular Tory politician. To be prime minister, however, it is usually thought essential to be a member of cabinet. He is not even a member of the Commons, though if he decided to seek a seat through a byelection, with the Heathrow issue as a ready-made cause/excuse, there is more than one Conservative MP ready to step down for him. But for Mr Cameron's allies to find consolation from the mayor being in no current position to strike is to miss an essential point. The threat is not of a leadership challenge any time soon. The mayor casts a shadow over the prime minister because he allows the Conservative party to imagine how things could be different with someone else in charge. The dream might well be a delusion, but it is nevertheless a seductive fantasy for a growing number of Tories. Boris is a walking, wisecracking reminder to them and to David Cameron of what the Tory leader has lost since he moved into Number 10.

Mein Blog befasst sich in einem umfassenden Sinn mit dem Verhältnis von Wissen, Wissenschaft und Gesellschaft. Ein besonderes Augenmerk richte ich dabei auf die Aktivitäten des Medien- und Dienstleistungskonzern Bertelsmann und der Bertelsmann Stiftung.