Scott Ritter, who used to head the UN weapons inspection team, said the obstruction had allowed Iraq to pose an even greater threat to world peace.

The BBC's Feargal Keane reports

He says Britain and the United States created an illusion of arms control in Iraq in order to save face.

Mr Ritter, former head of the UN Special Commission (UNSCOM) team in charge of disarming Iraq, resigned in August saying it was no longer possible to do his job.

"I resigned because I was being asked to do a job that was duplicitous."

Presidential sites were thought to house weapons

"We were trying to do a job and were being pushed by the United States and the United Kingdom towards something that would produce the illusion of arms control rather than our stated policy of disarming Iraq."

Mr Ritter claimed that Derek Plumbley, head of the British Foreign Office's Middle East section, told the Americans and the United Nations in July that London would not support planned inspections of presidential sites in Iraq, where many of the wepaons of mass destruction were thought to be stored.

He said Iraq would have stopped the inspections and created a situation which would have demanded action from the United Nations.

Faced with a lack of international and domestic support, the US and Britain backed down, he said.

Iraq stopped co-operating with UNSCOM in February.

Scott Ritter talks to the BBC

Although monitoring activities have not been stopped, Baghdad has barred surprise inspections of its military and industrial sites since 5 August.

Mr Ritter also said there was "no doubt" that lives would be lost if the commission was backed up by the UN with military force.

A unnamed Foreign Office official quoted by the Sunday Telegraph said that London had had a "very high regard" for Ritter when he was leading the UN weapons inpections teams.