Former naval officer Jeffrey Delisle, who spied for the Russians, was stripped of his commission, his service decorations and kicked out of the military Wednesday.
National Defence also announced the former intelligence officer will forfeit his severance pay, and the federal government will move immediately to recover the salary paid to him since his arrest in January 2012.
"Mr. Delisle's unauthorized disclosure of secret information is intolerable, inexcusable and inconsistent with the integrity and loyalty that Canadians expect from their men and women in uniform," Defence Minister Peter MacKay said in a statement.
Last week, Delisle was sentenced to 20 years in prison after pleading guilty to charges under security-of-information laws for passing top secret information to the Russians over a five-year period.
It's the second time in just over two years that the Governor General has been asked to revoke the commission of a serving officer.
Russell Williams was stripped of his rank of colonel in October 2010 after being sentenced to two terms of life in prison, with no chance of parole for 25 years, for the first-degree murders of Cpl. Marie-France Comeau and Jessica Lloyd.
The spy case has shaken trust in the Canadian military's ability to guard its secrets and those of the country's allies, according to testimony at Delisle's sentencing hearing.
MacKay tried to repair some of that broken trust by saying improvements are being made, but wasn't specific about what changes have been or will be made.
"I assure Canadians that our government continues to enhance our security procedures," he said.
"In recent years, the Department of National Defence has undertaken a complete functional review and rewrite of our security policy suite and has been working with other department bodies to synchronize and adopt best practices.
"In October 2012, we established a Director General Security Transformation organization aimed at charting the future for defence security policy."
The director of the Canadian Security Intelligence Service told a Senate committee Tuesday that Delisle was a quiet man, who made little fuss, making him hard to catch.
Richard Fadden says the damage done was "serious," but not "catastrophic."
Officials at National Defence have said little about how Delisle could have carried on for so many years raiding sensitive computer files belonging not only to Canada but to its principle allies.
Fadden told the Senate security and defence committee that no red flags were raised by the mandatory background security screening done on the intelligence officer, who served in some of the most sensitive posts in the military.
The fact Delisle had marriage and financial troubles wasn't enough for agents to probe further, he said.