John Major astonished at Iraq Way inquiry proposals

In a statement, Sir John - who was premier at the time of the first Gulf War - said the inquiry's findings risked being denounced as a "whitewash" unless there was full disclosure with witnesses giving evidence on oath.

"The Government's decision to hold the inquiry into the Iraq war in private is inexplicable - not least in its own interests," he said.

"Any material which puts our national security at risk must, of course, be withheld but if, as the Government proclaims, its position will be wholly vindicated, then it should welcome maximum publicity on all other disclosures.

"It should also engender confidence in its findings by taking evidence under oath. Only then can witnesses be bound to offer full and frank responses."

"The arrangements currently proposed run the risk of being viewed sceptically by some, and denounced as a whitewash by others. I am astonished the Government cannot understand this."

Sir John said the inquiry was needed to establish once and for all whether the war was legal or not, and to explain how and why the country was taken to war on a "false premise" about Iraq's weapons of mass destruction.

He said the Government also needed to provide some kind of closure for the families and friends of those who were killed or maimed in pursuit of its policy.

"If the Government is seen to obfuscate on this issue, lingering doubts will always remain," he said.

"It is imperative that, when next any British Government commits our armed forces to war, that Government's word is trusted beyond doubt.

"For this reason, and for the sake of all those who have either risked, or given, their lives in Iraq, nothing but an inquiry with full disclosure - under oath - will do."