Tony Blair has begun a lobbying campaign in Westminster to build support for action against Saddam Hussein.

The move comes amid predictions of a significant revolt by Labour MPs next week.

Number 10 announced last night that the prime minister will hold a private meeting with the Labour chairmen of key committees to gain their support ahead of the recall of parliament.

Though they will not see the secret dossier being prepared for MPs, Blair will brief influential MPs - including Chris Mullin, Bruce George and Donald Anderson - in the hope they will lobby colleagues on the backbenches.

It was also confirmed by Downing Street that the prime minister has agreed to appear before a special meeting of several Commons committees to face questioning on the UK's Iraq strategy later this year.

Both moves are aimed at showing that Tony Blair is seriously committed to dealing with Iraq and that he will not sideline the Commons as some critics on Labour's left have claimed.

The prime minister has agreed "in principle" to go before a special joint meeting - to be held in private - of the foreign affairs, intelligence, home affairs and defence select committees.

The meeting, which will be attended by all the committees' members, could take place as soon as November.

The prime minister has accepted that a precedent had been set last year when he went before a joint session of key committees to answer questions on the September 11 attacks.

Blair is "very enthusiastic" and all that remains now is for him to agree a date with the committee chairmen.

"The prime minister agreed that he is willing to build on that precedent," the foreign affairs committee chairman Donald Anderson told this website.

"He will go before the committees most appropriate to the issue."

But there were signals that for some MPs it was not enough.

The move had pre-empted a request from senior Labour MP, Dr Tony Wright, who had called on the prime minister to appear before a meeting of all Commons committee chairman.

He argued that the next scheduled meeting of the liaison committee should be brought forward from January to November.

Dr Wright, who runs the powerful public administration committee, argued Blair should meet before any critical Gulf decisions are taken and that Blair's latest offer was "not enough".

"It's not enough; it's a substitute to all the committees meeting," he said.

"It's very good though to do it as an addition to the debate but it's not the answer. It's a bit silly to be talking to the prime minister about this after the event has taken place," he told ePolitix.

Wright argued that having established a principle it was in effect a step backwards to have the prime minister being able to pick and choose who he spoke to and when.

"This doesn't answer the point, which is that we have developed a particular way now of talking directly to the prime minister. This is a prerogative power exercised by the prime minister to take the country into war and he has to be questioned about it at length," he said.