But the prime minister insisted that whatever the inquiry concluded he would not accept that it was wrong to invade Iraq.

Appearing before the House of Commons liaison committee this morning, Mr Blair told MPs: "I accept we now need a further inquiry."

Mr Blair's comments come after Sunday's White House announcement that it is to launch a bipartisan inquiry into its own intelligence about Iraqi weapons.

That followed the former Iraq Survey Group chief David Kay's concession that the American intelligence services had probably got it wrong in respect of Saddam Hussein's weapons programmes.

Mr Blair explained: "I think it is right, as a result of what David Kay has said - and the fact that the Iraq Survey Group now probably won't report, in the very near term, its final report - that we have a look at the intelligence that we received and whether it was accurate or not.

"Of course, the political judgments are in the end made by politicians. That is right. But I do simply say that, whatever is discovered as a result of that inquiry, I do not accept that it was wrong to remove Saddam Hussein or that the world is not a better and safer place without him."

He added that the foreign secretary, Jack Straw, would be making an announcement on intelligence and WMD to parliament later today.

Mr Blair conceded, however, that the government had yet to reach agreement with the opposition over the precise remit and membership of the inquiry.

"I hope we can secure agreement on this among all the political parties," he said.

The Conservatives and Liberal Democrats are known to be haggling over its precise remit and membership.

The prime minister added that the inquiry should "not be a re-run of the Hutton inquiry" nor an "inquiry into the political decision to go to war", which should be the preserve of government and parliament.

On its membership he revealed that it would include the leading cross-party members of the intelligence and security committee, and three other members. One of whom is believed to be the former cabinet secretary, Lord Butler.

Mr Blair also paid tribute to the intelligence services, stating that they do a "fantastic job for country", and adding that intelligence is "not an exact science".

Appearing on the BBC Today programme this morning, the shadow home secretary, David Davis, called for its terms of reference to be "as broad as possible". Criticism of the Hutton inquiry stemmed from the narrowness of its terms of reference, he claimed.