Tony Blair has defended the government's actions in relation to intelligence about Iraq's weapons of mass destruction.

Quizzed by a committee of senior MPs he said the government had acted properly before and during the war against Saddam Hussein.

"I'm quite sure we did the right thing because not merely was he a threat to his region, to the wider world, but it was an appalling regime that the world is well rid of," said Blair.

"And I think that the British army and the British people can be proud of the part they played.

"I refute any suggestion that we misled either parliament or the people totally. I think we made the right case and did the right thing.''

And he denied any suggestion that Downing Street had exaggerated the risk posed by Saddam's weapons arsenal.

"That central allegation is completely and totally false," said Blair.

"There could not be a more serious allegation against a government."

Intelligence pointing to Iraq's weapons of mass destruction had been correct "at the time".

"I do stand by the central case. I also stand by the intelligence we put in the September dossier," the prime minister told the Commons liaison committee.

The content of the dossier had the seal of approval from the Joint Intelligence Committee, said Blair.

"All of that intelligence...was cleared by the security and intelligence services," he added.

Stressing that he was "not an intelligence expert" the prime minister said those working within the secret service were "very serious and deeply committed".

In an assured performance Blair rejected suggestions that the war would be illegal if the intelligence proves to be false.

He said: "I don't believe that the legal basis is in any doubt at all. I don't believe that our intelligence will be shown to be wrong at all. I believe it will be shown to be right."

On the so-called "dodgy dossier" Blair admitted to an error in compiling the document, but defended its content.

"The moment we realised I had made a mistake we admitted to it," he said.

"Once it emerged that that was the case we accepted that that was a mistake and we should have sourced it.

"We actually made that clear to parliament."

In the face of criticism from MPs, he conceded that the publication of the dossier could have been handled better.

"We have apologised already and said it was a mistake, we should have sourced the second part of it," he told the committee.

"But the information in it was correct, the briefing paper was indeed largely based on intelligence."

But the opposition said the prime minister had been caught out and demanded an apology.

"It is astonishingly arrogant of Tony Blair to act as if this is not a serious matter. Once again he has refused to admit that a mistake was made, and he has turned down the opportunity to put the record straight," said Michael Ancram.

"Mr Blair must now face up to the real issues that go to the heart of trust in the government."

The shadow foreign secretary repeated his party's demand for a "full independent judicial inquiry".

But Blair maintained that the war was entirely justified. Walking away from the threat posed by Iraq would have left the international community "completely powerless" to act against rogue states, he said.

Defending the way in which the decision to go to war was taken, he denied that he had excluded key Cabinet ministers from the discussions.

"We had massive parliamentary debate for six months. We then had a final parliamentary decision that we should go to conflict," he said.

"We had Cabinet meeting after Cabinet meeting debating this. The idea that I got together a couple of people in the office over a cup of coffee in the office and decided to go to war is somewhat far-fetched."

The prime minister said the Iraqi regime had been engaged in "an active programme of concealment" in the run up to war.

Quizzed by the committee the prime minister said the "the policy of containment was not working".

"I have no doubt...that he continued to conceal those weapons of mass destruction," he told MPs.

"I have no doubt at all that we will find evidence of Iraq's weapons of mass destruction programme."

It was "important that we allow the Iraq Survey Group to do its work" said Blair.

"Let us wait and see what they do actually find and in the interviews that they are now beginning to carry out with the scientists and the experts and the witnesses," the committee heard.

"I simply tell you my view is that I'm very confident that they will find the evidence that such programmes existed and that Saddam was developing them but tried to conceal them."

The prime minister said that turning Iraq around after years of misrule "will take some time".

"The test will be what does Iraq look like in a year's time," he said.

"The reconstruction was never going to be easy."

And he stressed that Britain would remain in the country "until the job is done".

The premier downplayed suggestions that "tens of thousands" of UK troops could be stationed in Iraq for up to four years.

But he said it was too early to tell what the exact level of British involvement would be.

The prime minister also told MPs that the remains of 300,000 bodies had been found in mass graves in Iraq.

This proved that Saddam was "more evil" that had been previously thought, concluded Blair.