Carne Ross, who was First Secretary responsible for the Middle East at the United Nations, accused the former government of issuing “lies” to the public about the dictator’s capacity to launch weapons of mass destruction.
He said that it was a "disgrace" that ministers failed to exhaust all peaceful options before going to war against Iraq.
Giving evidence before the Chilcot inquiry into the Iraq war, Mr Ross said that “nuanced” intelligence about the threat from Iraq was “massaged” into "more robust and terrifying" messages about Saddam’s supposed WMD.
Mr Carne, who served at the UN between 1997 and 2002, claimed that the British and United States governments were fully aware that there was no “substantial threat” from Iraq ahead of the war.