The House of Commons Foreign Affairs Committee has demanded the British government reveal full details of what it knew about a controversial claim that Iraq tried to acquire uranium ore for its nuclear programme from the African state of Niger.
The committee has written to British Foreign Secretary Mr Jack Straw with a detailed list of questions about the allegation which was included in the Government's original dossier on Iraqi weapons.
Doubt was cast on the claim after the International Atomic Energy Authority - the United Nations nuclear watchdog - said that documents it received relating to the claim were forged.
In the US, the White House said that a reference to the claim - which based on intelligence from MI6 - should not have been included in President George Bush's State of the Union address.
Ministers have continued to stand by the allegation, which they have said was based on information received from a foreign intelligence service which they could not share with the American CIA, as MI6 did not "own" the intelligence.
In his letter to Mr Straw, the committee chairman Mr Donald Anderson demanded to know when he had learned about the CIA's reservations about the intelligence.
"Why did neither you nor your officials disclose to the Committee, in either your written or oral evidence, before the Committee published its recent report, that the CIA had expressed reservations to the British Government on the uranium from Africa element in the September dossier?" he asked.
He noted that when Mr Straw had appeared before the committee last month he had been specifically asked by one MP why the Government had "at least not put some degree of health warning" over the Niger claim in the dossier.
He also demanded to know whether centrifuge parts needed for uranium enrichment and related documentation discovered buried at the home of an Iraqi nuclear scientist - which Mr Straw had referred to in a letter to the committee - were really 12 years old as reported in the press.
PA