Mr Livingstone recalled a visit at Easter to California, where he was denounced for an attack he had made on what he called "the most corrupt and racist American administration in over 80 years". He said: "Some US journalist came up to me and said: 'How can you say this about President Bush?' Well, I think what I said then was quite mild. I actually think that Bush is the greatest threat to life on this planet that we've most probably ever seen. The policies he is initiating will doom us to extinction."

"The democrats disliked Ronald Reagan ... but I can tell you the visceral dislike that they have for George Bush and his policies is something I have never seen before.