By Kylie MacLellan
LONDON (Reuters) - The chairman of a British public inquiry into the Iraq War that has been running for seven years said on Thursday he expected to publish his report mid-2016, prompting Prime Minister David Cameron to urge him to speed up the process.
The inquiry aims to shed light on every aspect of Britain's involvement with Iraq from 2001 to 2009, from the build-up to the U.S.-led invasion in 2003 to the withdrawal of combat troops, and to identify lessons that can be learned.
The Iraq War, and in particular the role of former Labour Prime Minister Tony Blair in leading the nation into it, are still live political issues in Britain and the inquiry has come under repeated criticism from lawmakers and relatives of those killed over how long it has taken.
"My colleagues and I estimate that we will be able to complete the text of our report in the week commencing 18 April 2016. At that point, national security checking of its contents ... can begin," John Chilcot said in a letter to Cameron published on the inquiry's website.
Chilcot said due to the length of the report - more than 2 million words - it would then take many weeks to prepare for printing, making publication in June or July most likely.
Cameron welcomed that there was now "a clear end in sight" for the inquiry, but said he was disappointed Chilcot did not believe it would logistically be possible to publish the report until next summer.
"I recognize that you have a significant task, but would welcome any further steps you can take to expedite the final stages of the inquiry," he said in a letter to Chilcot released by his office.
More resources will be provided to the inquiry team if it allows the report to be published sooner, Cameron said, adding that the government planned to take no longer than two weeks to complete the national security checking process.
Publication has been held up by so-called "Maxwellisation", a confidential process in which people who are to be criticized in the report are given advance copies so that they have a chance to defend themselves.
On Sunday, U.S. network CNN aired an interview with Blair in which he apologized for what he described as mistakes in planning and intelligence before the war, with media accusing him of trying to pre-empt the report's criticism.
Reg Keys, whose 20-year-old son Thomas was killed in Iraq, said seven years was too long.
"We, the families, believe that Sir John allowed this ridiculous Maxwellisation process to run on far too long," he told the BBC. "It went on for two years when six months would have been fine.
"All we will get now is a watered down version of all the criticisms that Sir John put to these civil servants and senior politicians."
(Additional reporting by William James; editing by Stephen Addison)