By Martin Bright writing in The Observer

The Foreign Office has effectively killed the publication of a controversial fly-on-the-wall memoir of the Iraq war by one of Britain’s most senior diplomats, which would have called the conflict ‘politically illegitimate’.

In a move that brought immediate accusations of censorship from its author, The Observer can reveal that Sir Jeremy Greenstock, Britain’s ambassador to the United Nations during the preparations for war in 2003 and the Prime Minister’s envoy to Iraq following the war, has been blocked in his efforts to reveal ‘certain truths’ about the conflict. He was uniquely well-placed to provide the inside story of the conflict and its aftermath.

But this weekend his publishers in Britain and America were set to pull the plug on the book after the Foreign Office demanded drastic cuts and the removal of references to conversations between Greenstock and the major players in the conflict, including Tony Blair and the Foreign Secretary, Jack Straw.

Greenstock told The Observer he was considering other ways of getting his story out: ‘My personal view is that it might be worth saying what I want to say rather than being censored to blandness.’

He refused to elaborate on what this might entail, but opposition politicians last night demanded that Parliament be allowed to question the former ambassador about the contents of his memoirs.

Greenstock, now director of the international affairs institution, the Ditchley Foundation, said it was a pity that the government’s culture of secrecy had prevented him from putting his experiences on the historical record.

Civil service rules prevent senior public servants from writing their memoirs without first submitting them for official approval. The Observer understands that the first two-thirds of Greenstock’s work, The Costs of War, were submitted to the Foreign Office in the spring, when officials indicated that there were only likely to be minor changes.

However, when the final manuscript was delivered in the summer, Downing Street was said to be ‘deeply shocked’ by reports of private ministerial conversations and the deliberations of the UN Security Council. It is now thought the Foreign Office has gone back through the book and demanded further cuts.

The American publisher, Public Affairs, has already removed the book from its online catalogue, and Random House in Britain is now thought unlikely to publish a watered-down version.

Extracts seen by The Observer show that Greenstock saw the conflict as ‘politically illegitimate, but militarily a startling success for the US-led coalition’. He said the decisions made to remove Saddam were ‘honourable’, but that the promise of the post-war period had been ‘dissipated in poor policy analysis and narrow-minded execution’.

In the catalogue entry, now withdrawn, Greenstock wrote: ‘In the UK retired public officials do not normally write books on events still current. I am breaking that convention because the lessons drawn from the saga in Iraq are too important to leave until later.’ Liberal Democrat foreign affairs spokesman Menzies Campbell said Greenstock should be called before Parliament to discuss his book: ‘There is an opportunity here for one of the committees of the house, Foreign Affairs or Defence perhaps, to show its independence from the government by requesting Sir Jeremy to come before it.’

The new chair of the Foreign Affairs committee chair, Mike Gapes, said there had been no communication with Greenstock concerning his book.

A Foreign Office spokeswoman said: ‘The book is still under discussion in keeping with the proper procedures.’

Although Greenstock said he had not yet decided to defintively pull the plug on the book, he indicated that the cuts required by the Foreign Office would leave little substance to his memoirs.

Publishing sources said the book was highly unlikely to see the light of day while Blair was still Prime Minister