Opening his independent investigation in London, Lord Brian Hutton said he proposed "at some stage" to summon Blair, who is facing his gravest political crisis after the suicide of government scientist David Kelly.

Defence Secretary Geoff Hoon, Blair's close aide and powerful media strategist Alastair Campbell, and BBC board of governors chairman Gavyn Davies will also be asked to appear before the probe.

"At some stage in the course of the inquiry I propose to ask the Prime Minister and the Secretary of State for Defence, Mr Geoff Hoon, to give evidence of their knowledge of the discussions which took place and the decisions which were taken in relation to Dr Kelly," Hutton said.

Blair may be forced to cut short his holiday in Barbados

The former chief justice in Northern Ireland made clear that the opposing sides in a row which has dominated British politics for weeks would not be allowed to use the inquiry to try to prove their cases.

Opposition politicians have called for the inquiry to examine the way the government presented intelligence in the run-up to the US-led war launched on March 20 against Saddam Hussein.

New revelations

Hutton, one of Britain's most senior jurists, limited himself to saying: "I sit to investigate the circumstances surrounding Dr Kelly's death."

Kelly was an expert on chemical and biological warfare and a former UN arms inspector in Iraq, whose body was found July 18 in woods near his home west of London with a slit wrist.

Hutton revealed that the scientist had heart disease and said, without giving details, that he was found with four electro-cardiogram electrode pads on his chest.

"It is clearly important that I and the public should have a very much more detailed and fuller picture of the facts", the judge added.

Dossier doubts

Kelly had been identified as the source of a BBC report claiming that Blair's government had "sexed up" a September 2002 dossier on Iraq and weapons of mass destruction.

The 50-page file notably included a claim that Iraq could deploy chemical or biological weapons in as little as 45 minutes.

According to the BBC radio report, that assertion was inserted despite reservations among intelligence chiefs.

Vigorous denials from Downing Street of the BBC story escalated into a heated row between the government and the public broadcaster.

Kelly took his life after a parliamentary grilling

With Kelly's funeral to be held next Wednesday, Hutton - who has already met the scientist's widow - said his inquiry would resume on August 11 at the Royal Courts of Justice in central London.

One of the first witnesses, he said, would be Andrew Gilligan, defence correspondent of BBC radio's Today programme, who aired the controversial report on May 29, a week after he met Kelly.

Blair, who ordered the Hutton probe last week, has said he will "cooperate fully" and indicated he would cut short his holiday in Barbados to appear if summoned.

Minute's silence

With the press asking questions about how Kelly was publicly identified and whether the government was partially to blame for his death, Blair strongly denied that he authorissed the leaking of the scientists' name as the source of the BBC report.

Hutton said that he would investigate how the name of Kelly, said by his family to have been under unbearable pressure over the affair, came to be put in the public arena.

Friday's inquiry opened with a minute's silence in memory of Kelly. Hutton, silver-haired, plum-voiced and dressed in dark suit and tie rather than the gowns which British judges usually wear in court proceedings, stood with his head bowed.