The British government's former top lawyer said today he initially believed a second United Nations resolution was necessary to justify invading Iraq in 2003, but later changed his mind a month before the war.
However, Attorney General Peter Goldsmith said former Prime Minister Tony Blair had not pressurised him to alter his view as critics of the conflict have long suspected.
Three days before the March 20th, 2003 invasion, Mr Goldsmith told parliament that the use of force was legal on the basis of previous U.N. resolutions.
However, giving evidence to an inquiry into Britain's role in the war, Mr Goldsmith admitted publicly for the first time that his fist impression was that UN resolution 1441, passed in November 2002, did not justify military action.
"My provisional view was that taking all these factors into the balance, there wasn't enough there. The balance came down in favour of saying no, a second resolution is needed," he said.
Prime minister Gordon Brown set up the inquiry last year to learn lessons from the conflict, but some in his ruling Labour Party fear it will damage their chances ahead of a parliamentary election due by June, with their party trailing in the polls.
Many Labour members of parliament and supporters remain angry over the government's decision to support former US president George Bush in the unpopular war.
Yesterday, the two most senior legal advisers at the Foreign Office in the run-up to the invasion said they believed that the use of force without a specific mandate from the United Nations meant the military action was illegal.
Mr Goldsmith himself had warned then Foreign Secretary Jack Straw that he was pessimistic that resolution 1441 could be used to justify military action shortly after it was passed.
That was still his view when he provided draft advice to Mr Blair in January 2003 about the legality of military action.
"The prime minister made it clear that he accepted that it was for me to reach a judgement and that he had to accept that," he said.
Mr Goldsmith told the Chilcot inquiry the UN resolution was not "crystal clear", and he changed his mind after discussions with Mr Straw, the British officials involved in the UN negotiations, and US legal advisers.
He said he had concluded by the end of February to give the green light to an invasion. However on March 7th, 2003, his advice to Mr Blair was that only "a reasonable case" could be made for force and still cautioned that a second UN resolution was the safest course of action.
But by March 13th, as attempts to achieve a resolution authorising war faltered and two days after meeting with Mr Blair, his definitive view was that military action would be legal.
He said Mr Blair had not pressed him on the issue at the meeting, but that he had wanted to give a clear verdict after being approached by the head of the armed forces.
"The prime minister didn't express any view," he told the inquiry. "Our troops deserved more, our civil servants deserved more. So therefore it was important for me to come down clearly on one side of the argument or the other which is what I proceeded to do."
Earlier, Mr Goldsmith told the inquiry Mr Blair had not welcomed advice he gave in July 2002 that there was no basis for conflict without further UN approval.
Mr Blair himself will make his eagerly awaited appearance on Friday, when he will be asked to explain why he sent 45,000 British soldiers to war in Iraq in which 179 were killed.
Reuters