That is the verdict of a Dutch panel. The Guardian:
In a series of damning findings, a seven-member panel in the Netherlands concluded that the war, which was supported by the Dutch government following intelligence from Britain and the US, had not been justified in law.
“The Dutch government lent its political support to a war whose purpose was not consistent with Dutch government policy,” the inquiry in the Hague concluded. “The military action had no sound mandate in international law.”
The British refused to release a letter, from Blair to the Dutch PM Jan Peter Balkanende.
“It was a surprise for our committee when we discovered information about this letter,” said Rob Sebes, a spokesman for the Dutch inquiry. “It was not sent with a normal procedure between countries – instead it was a personal message from Tony Blair to our prime minister Jan Peter Balkanende, and had to be returned and not stored in our archives.
“We asked the British government to hand over the letter but they refused,” Sebes said.
[...] The findings have prompted controversy in the Netherlands, where Balkenende has so far resisted calls for a formal parliamentary inquiry into his government’s decision to back the war.
However, the report is likely to influence analysis of the events in the UK, experts say, with senior judicial figures among those concerned that the Chilcot inquiry lacks the expertise on issues of legality in comparison to the Dutch panel.
“The findings of the Dutch inquiry that the war had no basis in international law are even more important for a domestic audience in Britain,” said Sands. “I do not see how the five members of the Chilcot inquiry, none of whom is legally qualified, could possibly summon the means to reach an alternative conclusion.”
The BBC:
The inquiry was launched after foreign ministry memos were leaked that cast doubt on the legal basis for the war.
The Netherlands gave political support to the 2003 invasion of Iraq, but had no military role.
[...] Mr Balkenende decided to join the “coalition of the willing” assembled by US President George W Bush because, he said, Saddam Hussein had consistently flouted UN resolutions and possessed weapons of mass destruction.
The Dutch parliament opposed the decision to back the invasion.
[...] The committee said there had been no UN mandate for the attack, putting the decision to join at odds with international law.
It said “the wording of [UN Security Council] Resolution 1441 cannot reasonably be interpreted as authorising individual member states to use military force”.


Letter from Straw to Blair, sent early 2002:
And, regarding Alistair Campbell:
By: Lister on January 17, 2010
at 12:04 pm