The judge heading the inquiry into the circumstances surrounding the death of Iraq arms expert Dr David Kelly says it will be for him alone to decide the scope of the investigation.
Dr Kelly was questioned by MPs days before his apparent suicide
Lord Hutton also said he intended to carry out the inquiry "urgently" and to conduct most of it in public.
Dr Kelly's body was found in woodland near his home in Oxfordshire on Friday. An inquest was opened and adjourned on Monday during which the coroner said the cause of death was "a haemorrhage due to an incision to his left wrist".
Lord Hutton's statement comes as pressure mounts on the BBC following its confirmation that Dr Kelly was the principal source for its story claiming Downing Street had "sexed up" an Iraq weapons dossier.
Lord Hutton said the government had stated "it will provide me with the fullest cooperation" and expects all other authorities and parties to do the same.
The peer said he intended to explain how he would conduct the inquiry in public "in the near future", but the timing would take account of the date of Dr Kelly's funeral and the inquest into his death.
Lord Hutton said: "I make it clear that it will be for me to decide as I think right within my terms of reference the matters which will be the subject of my investigation."
Lord Hutton said he aimed "to report as soon as possible".
Last week Dr Kelly told MPs he had spoken to BBC correspondent Andrew Gilligan but did not believe he was the main source for the report on BBC Radio 4's Today programme.
Lord Hutton is expected to look into two crucial points - how Dr Kelly's name was made public, and what exactly he said when he met both Mr Gilligan and fellow BBC reporter Susan Watts to talk about Iraq's weapons of mass destruction.
Mr Blair has rejected opposition calls for the inquiry to examine the wider issue of the government's use of intelligence on Iraq and for a recall of Parliament.
Asked if he would block Lord Hutton broadening the scope of the inquiry into the general case for war with Iraq, Mr Blair said: "I think it is important that he does what we've asked him to do".
The prime minister, who is in Beijing on a tour of the Far East, has already confirmed he will personally give evidence to the inquiry.
Government officials from Downing Street and the Ministry of Defence, as well as the BBC, are also expected to be questioned.
But Robin Cook, who quit the government over Iraq, said: "I think it would have been much better if the government
had responded two months ago and set up a judicial inquiry into the full facts
of the case then and the history of the last two months might have been very
different if they had."
Following weekend reports, Downing Street said Dr Kelly had been given "a verbal reprimand" about talking to the press by the MoD, but denied any threat being issued to his pension.
The BBC's confirmation that Dr Kelly was the principal source for Mr Gilligan's story, as well as similar reports by Ms Watts on BBC Two's Newsnight programme, has raised more questions about the affair.
Just days before he was found dead Dr Kelly had appeared before the foreign affairs select committee - during which he said he did not believe he was the main source for Mr Gilligan's report.
Mr Gilligan denied he had "misquoted or misrepresented" Dr Kelly, in a statement on Sunday.
The statement was issued after BBC director of news Richard Sambrook revealed Dr Kelly was the report's principal source, after speaking to his family.
Mr Sambrook's statement prompted Dr Kelly's local MP, Tory Robert Jackson, to call for the resignation of the BBC chairman Gavyn Davies.
Mr Gilligan's report said "a senior official" had told him the claim that Saddam Hussein's "military planning allows for some of the weapons of mass destruction to be ready within 45 minutes of an order to use them" had been "included in the dossier against our wishes because it wasn't reliable".
On Sunday, Mr Gilligan said Dr Kelly had "expressed very similar concerns about Downing Street interpretation of intelligence in the dossier and the unreliability of the 45-minute point" in both a meeting with him and a separate interview with Ms Watts for Newsnight.
'Respect and restraint'
Mr Sambrook said the corporation believed it correctly interpreted and reported the information obtained from Dr Kelly during interviews.
On Monday's Today programme former cabinet minister Peter Mandelson said the BBC governors had made a "crass error" in investing all the "authority and credibility" of the BBC in defending the original report.
On the same programme, Clare Short said that the death of Dr Kelly was a "complete tragedy" and that the inquiry would have to examine whether there "was an abuse of power by the Downing Street machine".
But she said the row with the BBC was a "distraction" and that the questions over Dr Kelly's death were a separate question "from the main question of how we got to war with Iraq".