From spying failures to spin, the issues Butler must address

Tony Blair remained defiant yesterday that intelligence about Iraq's weapons had been correct as he awaited publication of Lord Butler's report today. Asked if he had been fed "duff" information about Iraq's weapons of mass destruction, the Prime Minister insisted: "I don't accept that at all."

Tony Blair remained defiant yesterday that intelligence about Iraq's weapons had been correct as he awaited publication of Lord Butler's report today. Asked if he had been fed "duff" information about Iraq's weapons of mass destruction, the Prime Minister insisted: "I don't accept that at all."

On the eve of the former cabinet secretary's verdict on the use of intelligence before the war, Mr Blair repeated that the war was justified. "I feel very much as I did 18 months ago," he said. "I think it is very difficult to look at Iraq today, to look at Iraq under Saddam, and say we would be better off, the world would be safer, we would be more secure, if Saddam was still in charge of Iraq."

An advance copy of Lord Butler's report was formally delivered to Downing Street just after noon yesterday, but Mr Blair read it only after his afternoon press conference with the Italian Prime Minister, Silvio Berlusconi.

The Prime Minister ordered the inquiry in February, after growing public concern about the failure to uncover weapons of mass destruction in Iraq.

Mr Blair had wanted to establish a cross-party committee of inquiry under Lord Butler, the former cabinet secretary. But both the Liberal Democrats and the Tories refused to participate in the inquiry, amid concerns that its remit would not cover the controversy over the use of intelligence information by ministers in the preparation for war.

But Michael Mates, the former Conservative Northern Ireland minister, agreed to serve on the five-strong panel in a personal capacity. The other members are the Labour MP Ann Taylor, chairman of the Parliamentary Intelligence and Security Committee; Sir John Chilcot, a career diplomat and staff counsellor for the security and intelligence services, and Field Marshal Lord Inge, the former chief of the defence staff. The inquiry appears to have taken a broad interpretation of its remit, asking searching questions about Downing Street briefings on the now-notorious "45-minutes" claim and taking evidence from the former UN chief weapons inspector, Hans Blix.

The inquiry was established to investigate the intelligence "coverage" on weapons of mass destruction in rogue states. Its remit was to look at the accuracy of intelligence on Saddam Hussein's arsenal and examine discrepancies between intelligence "gathered, evaluated and used by the Government before the conflict" and between that intelligence and what has been discovered by the Iraq Survey Group since the end of the war.

The committee took evidence in private, although it could call for written and oral evidence from across government and beyond. Mr Blair will give the Government's response in a statement to MPs in the Commons at 1.30pm.

Were there fundamental flaws in the way intelligence was collected?

Something has obviously gone wrong when confident assertions that Iraq possessed weapons of mass destruction have to be abandoned. Sir Richard Dearlove, head of MI6, insisted the now notorious 45-minute claim was a "well sourced piece of intelligence". Sir Jeremy Greenstock, Britain's former ambassador to the UN, later admitted that too much reliance may have been placed on Iraqi exiles.

Were there major problems with the interpretation of information by the Joint Intelligence Committee?

John Scarlett, the committee's chairman, was ultimately responsible for a complex series of assessments of intelligence before it went into the Government's dossier. David Kay, the former head of the Iraq Survey Group of weapons inspectors, has claimed intelligence officials failed to start with a blank sheet of paper.

What caveats were present in the intelligence assessment of Saddam Hussein's arsenal? Were they ignored?

The precise wording of the Government's dossier on Iraq's weapons of mass destruction caused a row among intelligence analysts. Brian Jones, former head of the nuclear, chemical and biological branch of the MoD's Defence Intelligence Staff has produced a damning critique of the way the Prime Minister crushed caveats into certainties.

What is the truth of the claim that Saddam attempted to acquire uranium from Africa?

The claim that Saddam attempted to buy uranium yellowcake from Niger has been dismissed, both by the International Atomic Energy Authority and by the American administration. The Government, however, insists that it had intelligence from an unnamed third party and has stood by its assertion. Lord Butler is known to have taken evidence from Hans Blix, the former UN chief weapons inspector and Mohamed ElBaradei, head of the IAEA.

Did the intelligence agencies and the Joint Intelligence Committee bow to political pressure to strengthen the case against Saddam?

Lord Hutton found that John Scarlett may have been "subconsciously influenced" by the Government's desire to have as strong a case as possible against Saddam. Alastair Campbell, the former Downing Street director of communications, made it clear that ministers wanted the dossier on Iraq's weapons to be as strong as possible.

Did Downing Street "spin" the 45-minute claim?

The claim that Saddam could deploy chemical and biological weapons within 45 minutes of an order to do so was in the foreword of the Government's September dossier. Lord Butler has written to the editors of provincial newspapers asking whether Downing Street briefed them about Saddam's ability to use WMD against British targets.

Did the Attorney General change his advice on the legality of war to suit the Government's political demands?

Lord Goldsmith fell back on existing UN resolutions and Saddam's failure to co-operate with UN weapons inspectors. The Attorney General's advice conflicted with that of other senior law officers. However, the Attorney General is expected to be cleared.

Is it right that John Scarlett should be promoted to head of MI6?

Tony Blair is facing all-party pressure to block the appointment because of Mr Scarlett's role in producing intelligence about Iraq which has proved to be false. Yesterday Downing Street insisted that Mr Blair had full confidence in him.

Has Tony Blair's presidential style contributed to intelligence failings?

Lord Hutton revealed the importance of informal discussions at the heart of Government. Critics have also claimed that power is concentrated among a small group of unelected advisers in Downing Street. They claim that such an informal style weakens the checks and balances which have traditionally operated across Whitehall.

How should the intelligence services avoid making the same mistakes again?

The Government has already pledged to double spending on security and recruit another 1,100 staff to MI5, MI6 and GCHQ. There will be a new emphasis on recruiting Arabic speakers in an effort to infiltrate al-Qa'ida cells and ministers claim information sharing around the world has improved. Britain has so far avoided a major terrorist attack, but any attempt to use intelligence to justify future military action would be met with scepticism.