Tony Blair has said he will not step down as prime minister despite coming under pressure to consider his position as a result of the death of Dr David Kelly.

Speaking on Sunday, the prime minister said he was "absolutely" determined to carry on in office.

But with the latest crisis described in the media as the most serious since Labour took office in 1997, he remains under serious pressure and intense scrutiny.

And the Kelly crisis follows continuing rows with the BBC and the failure to discover any weapons of mass destruction in Iraq.

The government has also battled to win support for controversial policies on foundation hospitals and top-up fees.

But despite the difficulties, Blair indicated he would press on with his programme for government.

"Because of the seriousness of what's happened, because somebody has died as a result of the events of the last few weeks, it's right that we have an inquiry," he told Sky News' Sunday With Adam Boulton programme.

He added that there would be lessons from the tragedy for both politicians and the media.

"And of course, someone in my position has got strong views about that, but now is not the moment to do that."

The prime minister also said he would take responsibility for the actions of his officials, such as Number 10 communications director Alastair Campbell.

Campbell's role is set to face scrutiny by the independent inquiry into Dr Kelly's death, which is to be headed by senior judge Lord Hutton.

"In the end the government is my responsibility and I can assure you the judge will be able to get to what facts, what people, what papers he wants," Blair said.

Asked about the wave of criticism he was facing, the prime minister said that some came from people who had been opposed to the war in Iraq from a start.

"As for the rest, you have got to have broad shoulders in this job. I have got them," he said.

"Obviously I believe that I'm doing the right thing for the country otherwise I wouldn't be doing the job.

"I have been through quite a few times when people have said, this is a terrible situation and all the rest of it. It depends on whether you believe in what you are doing."

Asked if he had the appetite to go on, the prime minister replied: "Absolutely."