By Nigel Morris, Deputy Political Editor
Britain was taken to war in Iraq on the basis of "lies", scaremongering and deliberate exaggeration, a former UK diplomat told the Iraq inquiry.
Carne Ross claimed that Britain and the United States privately did not believe that Iraq's weapons programmes posed a "substantial threat" before launching the 2003 invasion.
Mr Ross, the former first secretary at the UK's mission to the United Nations, told the Chilcot inquiry there was no "significant intelligence" to support claims that Saddam Hussein had amassed an arsenal of deadly weapons.
He argued that Saddam could have been contained through sanctions - and condemned the failure by the US or UK to close the Iraqi dictator's bank accounts in Jordan.
Mr Ross, who resigned before the war, pointed to a document circulated to Labour MPs in 2002 as evidence of a "process of deliberate public exaggeration", including the claim that Saddam could develop nuclear weapons within five years.
He added: "This paper also contains such scare-mongering claims as ‘less than a teaspoon of anthrax can kill over a million people' without explaining the extremely difficult process for anthrax to be weaponised and delivered in an effective method."
The former diplomat said the September 2002 dossier that made the case for war - including the notorious claim that Iraq could launch a missile strike within 45 minutes "misrepresented" the raw intelligence.
He said a "very uncertain and patchy picture" was converted into "positive claims of knowledge of threat".
Mr Ross concluded: "This process of exaggeration was gradual, and proceeded by accretion and editing from document to document, in a way that allowed those participating to convince themselves that they were not engaged in blatant dishonesty.
"But this process led to highly misleading statements about the UK assessment of the Iraqi threat that were, in their totality, lies."
Mr Ross challenged the inquiry to publish all Government documents concerning the war. He alleged that the evidence given by some officials was contradicted by papers he had seen and added he had seen "very little" in classified documents that could not be made public.