Increasingly concerned that Blair was ignoring his earlier advice that regime change was "not a legal basis for military action", on 29 July 2002 Goldsmith wrote to Blair on what the Mail on Sunday described as "a single side of A4 headed notepaper".

The typed letter was addressed by hand, "Dear Tony", and signed by hand, "Yours, Peter". In the letter, whose existence was confirmed by other sources, Goldsmith warned that the UN charter permitted "military intervention on the basis of self-defence", but it did not apply here because Britain was not under threat from Iraq; that the UN allowed "humanitarian intervention" in some circumstances, but such was not the case in Iraq; and that it would be very difficult to rely on earlier UN resolutions approving the use of force against Saddam.

Goldsmith is reported to have ended his letter saying "the situation might change".

Blair not only ignored Goldsmith's letter, he banned the attorney from attending cabinet meetings. Goldsmith was so angry that he threatened to resign – and lost three stone in weight as Blair and his closest advisers gagged him, according to the Mail on Sunday.

I'll make it legal

That’s a hell of an allegation, and obviously what a lot of people suspected at the time.

Certainly so, because it adds weight to the case against Blair (and Bush, probably) for war crimes. If this letter still exists and it can be proven to have been read by Blair, he could find himself on a short trip to The Hague.

Certainly so, because it adds weight to the case against Blair (and Bush, probably) for war crimes. If this letter still exists and it can be proven to have been read by Blair, he could find himself on a short trip to The Hague.

"I can't accept collective responsibility for the decision to commit Britain now to military action in Iraq without international agreement or domestic support."