Tonight Barack Obama hits town. For some reason his office has not yet got in touch with Notebook to set up a meeting. He may have some very bright people working for him, but clearly they have a lot to learn.

On Saturday the presidential candidate will be meeting Gordon Brown, the prime minister, and also his predecessor, Tony Blair, in his capacity as Middle East peace envoy. But you could hear the screams of anticipation all over London last week when it was revealed that the Tory leader, David Cameron, was also going to be granted a brief audience.