The revelation of Joseph Wilson's investigation in the African state forced President George Bush to retract claims about Iraq's attempts to buy uranium made in his State of the Union speech two months before the war began.
The Administration is alleged to have leaked the name of Mr Wilson's wife, an undercover CIA operative in the field of weapons of mass destruction, with the aim of discrediting him. It is said that Mr Wilson was selected to go on the trip to Niger last year only after his wife, Valerie Plame, suggested him.
US intelligence officials and the Democrats are furious about the move, arguing that it jeopardises Ms Plame's work and undermines her husband. They have called for an inquiry.
Her identity was revealed by Bob Novak, a syndicated columnist, who said that he was given the information by "two senior administration officials". They told him that Ms Plame had suggested to her CIA colleagues that her husband should be sent on the mission.
His report was followed by allegations on neo-conservative websites that Mr Wilson was an opponent of the Iraq war, and had an interest in refuting the threat from Saddam Hussein's WMD.
Mr Wilson said yesterday that the naming of his wife had parallels with the disclosure of the identity of the British scientist David Kelly, the source of BBC allegations that the British government "sexed up" an dossier on Iraqi weapons.
"The Administration in Washington came in saying they were going to restore honour and dignity to the presidency," Mr Wilson said. "They have shown no sign of it so far.
"This is highly damaging to my wife's career, and could be seen as a smear against me."
But it was also about discouraging "others who may have information embarrassing to the administration from coming forward," he said.
"It is absolutely untrue that my wife was responsible for my trip to Niger. I met a number of senior members of staff to discuss the visit."
Democrats have criticised the White House over disclosing Ms Plame's identity, and Senator Charles Schumer of New York has urged the FBI to investigate.
Former US intelligence officials have also attacked the Administration for the leak, saying it put Ms Plame at risk.
Frank Anderson, the former CIA station chief for the Near East Division, said: "When it gets to the point of an administration official acting to do career damage, and possibly endanger someone's life, that's mean, that's petty, it's irresponsible, and it ought not to be sanctioned."
Kim Sengupta Independent UK 04 August 2003
