The lies of two Iraqi spies were central to the claim - at the heart of the UK and US decision to go to war in Iraq - that Saddam Hussein had weapons of mass destruction. But even before the fighting started, intelligence from highly-placed sources was available suggesting he did not, Panorama has learned.

Six months before the invasion, the then Prime Minister Tony Blair warned the country about the threat posed by Saddam Hussein's weapons of mass destruction (WMD).

"The programme is not shut down," he said. "It is up and running now." Mr Blair used the intelligence on WMD to justify the war.

That same day, 24 September 2002, the government published its controversial dossier on the former Iraqi leader's WMD....