Robin Cook, the British minister who resigned in protest before the war on Iraq began, has accused the British government of using intelligence selectively to justify its decision to go to war.
Another former minister, Clare Short, who resigned after the war, accused Prime Minister Tony Blair of deciding on a date for war despite the fact that diplomatic negotiations were continuing.
They were giving evidence to MPs on the House of Commons Foreign Affairs Select Committee.
The Committee is investigating conflicting claims over the existence of Iraq's weapons of mass destruction and the British government's use of intelligence.
The committee's first witness - former Foreign Secretary and leader of the House Robin Cook - said a lot of the intelligence published before the war was wrong and was used to fit conclusions the government had already reached.
He told the Commons Foreign Affairs Select Committee that the government had scored what he called a 'spectacular own goal' in publishing a dossier about Saddam Hussein's weapons of mass destruction on the Downing Street website.
He said the threat posed by Saddam was exaggerated and that it was strange that 10,000 litres of anthrax remained undiscovered despite the fact that most of the senior people in the Iraqi weapons programme were now being offered vast rewards to lead coalition inspectors to the material.
Clare Short told the committee that senior sources in Whitehall have told her that Tony Blair had given a commitment to George Bush to go to war by last spring, despite the fact that diplomatic efforts to avoid war were continuing.
Ms Short said the UN chief weapons inspector, Hans Blix, should have been given more time.
Mr Blair has refused to appear before the committee, which will publish its report next month.
CIA accused of manipulation
In a related development, a senior Democratic Senator in the United States has accused the Central Intelligence Agency of manipulating information before the war.
Senator Carl Levin said he has evidence that the UN weapons inspectors were not given all the best US intelligence on possible sites of weapons of mass destruction.
Marvin Ott, a former senior analyst with the CIA, said the integrity of intelligence provided to the Bush Administration would have serious implications for any future military campaign by the US.
