Parliament's intelligence and security committee is to investigate the information on Iraq's illegal weapons handed to ministers by the security services.

The foreign affairs select committee is also set to conduct an investigation.

It will focus on whether the Foreign Office and the government "presented accurate and complete information to parliament in the period leading up to military action in Iraq, particularly in relation to Iraq's weapons of mass destruction".

Meanwhile, John Reid, the leader of the Commons and a close ally of the prime minister, has attacked parts of the security services.

He told today's Times: "There have been uncorroborated briefings by a potentially rogue element or indeed rogue elements in the intelligence services.

"I find it difficult to grasp why this should be believed against the word of the British prime minister and the head of the joint intelligence committee."

The Times also claims that Hilary Armstrong, the chief whip, told colleagues that the government was the victim of "skulduggery" in the intelligence services.

Iain Duncan Smith wrote to the prime minister last night, demanding urgent answers to five key questions over the missing weapons.

"Serious allegations are now being made, allowing others to cast doubt on statements made by you and your ministers," he said.

"My concern is that this will have a detrimental effect on the ability of the government and the armed forces to complete their task in Iraq, unless things are cleared up quickly."

Tony Blair is expected to set out his position when he faces MPs at prime minister's questions later today.