Britain has the world's most favourable libel laws for those libelled. Before the Observer published extracts from Andrew Rawnsley's book today, you can be sure every word was crawled over by the paper's libel lawyers; accusing a sitting Prime Minister of such thuggish, oafish behaviour that would have seen anyone else in front of an employment tribunal long ago cannot have been done lightly or negligently.
Rawnsley has described his sources as '24 carat', and the fact that we're reading details of Brown's disturbed and psychotic behaviour this morning supports that claim. Brown's counter-claim that it's 'All lies' can be discounted as a last desperate lie from a man unaquainted with the truth - and one action and one action only will demonstrate Brown's mendacity or otherwise.
If Rawnsley's story is untrue, Brown must sue. If he doesn't sue, we can all safely assume that every word is true.