CLEARLY, Katherine Gun, an employee at the Government's GCHQ spy-centre, was guilty of a breach of the Official Secrets Act by leaking a memorandum about an American espionage operation to spy on the UN offices and homes of ambassadors of countries with a vote in the Security Council; the operation was designed to find out how these countries would vote in the Council's resolutions on Iraq. We know that Ms Gun was guilty because she pleaded guilty when her trial began at the Old Bailey this week. How could it happen, therefore, that the Crown Prosecution Service could suddenly decide on Wednesday not to proceed with its case “on legal grounds”? At his media conference yesterday the Prime Minister claimed that he had taken no part in the decision to abandon Ms Gun's prosecution. It had been the Attorney-General's decision, in consultation with the Foreign Secretary, said Mr Blair, but he did not explain how the prosecution had even got started if there were legal problems with it. Given the involvement of the United States in the case and the general air of crisis hanging over the intelligence services of both countries it seems extraordinary that Mr Blair was not privy to any reservations his legal officers may have had about the prosecution. It's not quite as bad as not knowing what kind of weapons of mass destruction you're talking about, but it comes pretty close. The conclusion that most people will come to is that if Ms Gun's trial had proceeded the evidence would have been deeply embarrassing to the Government in relation both to the legality of the war in Iraq and to its relationship with the White House. Clare Short's revelations on the Today programme yesterday simply served to underline this impression.