Attorney General Lord Goldsmith complained that Ministers put him in a "difficult position" by claiming Britain could use force against Iraq without a further United Nations mandate, it was revealed today.
Lord Goldsmith warned a year before the 2003 invasion that he was not aware of evidence of an imminent threat which would justify military action without UN Security Council authorisation, a letter released by the Iraq Inquiry showed.
He wrote to Geoff Hoon in March 2002 complaining that the then-defence secretary had given an interview in which he made a "clear statement" that Britain would be "perfectly entitled" to use force against Iraq without a specific UN resolution.
Lord Goldsmith pointed out that he had not been asked at this point to advise on the legality of possible military action against Saddam Hussein.
He said he would not want to give a definitive statement without full background information, but stressed that he saw "considerable difficulties" in justifying the use of force on the basis of self-defence.
The letter, dated March 28 2002, followed an interview Mr Hoon gave to Jonathan Dimbleby in which he referred to the legal position on military action against Iraq.
Lord Goldsmith wrote: "I noted that you made a clear statement that we would be perfectly entitled to use force without a specific United Nations resolution and that there is no legal necessity to go back to the United Nations.
"As you are aware, the Law Officers' opinion has not been sought on the legality of possible action and I have not therefore offered any views on the legal position.
"The clarity of your statement and the apparently authoritative way it was produced puts me however in a difficult position."