Sir Jeremy Greenstock, who was Britain's ambassador to the United Nations before the conflict and the UK's highest official in the post-war Coalition Provisional Authority, said he was still negotiating with the Foreign Office over the contents of his memoir, The Costs of War.
Sir Jeremy said he was not certain when or even if the book would now be published. The original publication date was March 2006, but this deadline will not be met. "The timing of when to publish will be my decision when I decide to make it," he said. "I just have to decide what revisions can be made."
The book was described in publicity material as "remarkably candid" by Greenstock's US publishers, PublicAffairs, but they have now removed it from their online catalogue.
Civil service rules prohibit public servants from writing their memoirs without first submitting them for official approval.
Sir Jeremy said that the book was not a "tell-all", but added that it was under "continuous discussion" with the Foreign Office. "The concern is centred on what I put into the public domain," he said. "I accept that a judgement has to be made that is in the interests of diplomacy. I accept that mine may not be the only view. I don't want to write something that makes the job of my former colleagues more difficult."
A Foreign Office spokesman said: "The book is still under discussion, in keeping with proper procedures."