LONDON, Dec 1 (Reuters) - Britain’s government gave secret assurances to Washington it would limit the scope of an inquiry into the Iraq war to protect U.S. interests, according to diplomatic messages leaked by a whistle-blowing website.

U.S. embassy cables obtained by WikiLeaks reported a British official, Jon Day, as telling U.S. officials in 2009 that Britain had “put measures in place to protect your interests” during the inquiry.

The documents were postedhere.

The inquiry was set up in 2009 by former Prime Minister Gordon Brown to learn lessons from the Iraq conflict, the most controversial episode in the 10-year premiership of Tony Blair, Brown’s predecessor.

Critics have long argued that Blair promised former U.S. President George W. Bush in April 2002 that Britain would support military action to get rid of Iraqi leader Saddam Hussein, and then exaggerated intelligence reports about weapons of mass destruction. No such weapons were ever found.

A spokeswoman for the inquiry said she would not comment on leaks.

“The Iraq Inquiry is independent of the British government. The protocol agreed between the Iraq Inquiry and the government allows for material to be withheld from publication if publication would damage international relations,” she said.

The Foreign Office issued a similar statement and the Ministry of Defence had no immediate comment.

The chairman of the Iraq committee, John Chilcot, has said the inquiry was not a trial but would make criticisms where warranted. He has defended his team from criticisms that they had been too soft on witnesses and that the inquiry would be a whitewash.

The protection mentioned by Day in the leaked cables would be for U.S. intelligence documents supplied before the Iraq war. They could not be brought to light because of the damage that would do to the Anglo-American alliance, they showed officials as saying.

The Sept 22 cable reported a meeting held in London earlier that month between U.S. officials including Under Secretary of State Ellen Tauscher and then British Foreign Secretary David Miliband and several senior officials including Day, the Ministry of Defence Director General for Security Policy.

Andrew Burgin, a spokesman for Stop the War Coalition, called the reported assurances given to Washington “despicable and an affront to the democratic procedures of this country.”

“This was meant to be a full public inquiry and we can see that assurances have been given that American interests will not be embarrassed and it is necessary now I think for us to have a new inquiry and for that documentation, if it has been suppressed, to be released,” he told Reuters.

The decision to go to war provoked huge protests, divisions within Blair’s Labour Party and accusations he had deceived the public about the reasons for invasion. (Writing by William Maclean, Editing by Jon Boyle)