Iraq inquiry: Notes from Tony Blair to George Bush will not be published - The Guardian

John Chilcot, the chairman of the Iraq war inquiry, described the notes as 'central to its work'. Photograph: Matt Dunham/PA

Britain's top civil servant is refusing to allow the official inquiry into the invasion of Iraq to publish notes sent by Tony Blair to George Bush – evidence described by the inquiry as essential in establishing the circumstances that led to war.

The cabinet secretary, Sir Gus O'Donnell, has denied repeated requests for the notes to be declassified. In sharp exchanges with O'Donnell, inquiry chairman, Sir John Chilcot – who has seen the notes – described them as "central to its work".

He added: "The material requested provides important, and often unique, insights into Mr Blair's thinking and the commitments he made to President Bush, which are not reflected in other papers."

O'Donnell refuses to release the papers on the grounds that disclosure would damage Britain's relations with the US as well as future communications between a British prime minister and a US president.

Earlier this month, in a third letter to O'Donnell, Chilcot wrote: "The question [of] when and how the prime minister made commitments to the US about the UK's involvement in military action in Iraq and subsequent decisions on the UK's continuing involvement, is central to its considerations."

He referred to passages in memoirs including Blair's autobiography and disclosures by Jonathan Powell, the then prime minister's chief of staff, and Alastair Campbell, his former head of communications.

Those publications, and the refusal to disclose Blair's notes, Chilcot noted in a stinging passage, "leads to the position that individuals may disclose privileged information (without sanction) whilst a committee of privy counsellors established by a former prime minister to review the issues, cannot".

The standoff between Chilcot, a former senior civil servant, and the cabinet secretary comes as the inquiry prepares to question Blair in person.

It has summoned the former prime minister back to press him about what he promised Bush in private, and why he ignored advice by his government's chief law officer, Lord Goldsmith.

One document, previously leaked, notes that Blair told Bush at a meeting in Washington on 31 January 2003 – less than two months before the invasion – that "he was solidly with the president".

This was after Bush told Blair that military action would be taken with or without a new UN resolution, and that bombing would start in mid-March.