OTTAWA — Two men who hid their pasts as wartime Nazi collaborators have been stripped of their Canadian citizenship by the federal cabinet.

Helmut Oberlander and Jacob Fast now face deportation hearings.

It's the second time Mr. Oberlander's citizenship has been revoked. He lost it first in 2001, but the Federal Court of Appeal overturned the ruling in 2004 and ordered cabinet to reconsider.

In 2000, a court ruled that when Mr. Oberlander came to Canada in 1954, he concealed his membership in a Nazi extermination squad which conducted mass executions of Jews and other civilians in the former Soviet Union. He was a translator for what was essentially a mobile killing outfit.

In 2003, another the court said Mr. Fast hid his German citizenship when he came to Canada in 1947 and that he had collaborated with a Nazi security police unit in Ukraine which arrested and executed Jews.

Supporters of the two men have long argued that they were forced to collaborate and never participated in the actual killings.

Liberal MP Andrew Telegdi, who has long demanded a complete reworking of the Citizenship Act, said the Oberlander case is an abuse because the cabinet shouldn't be involved.

“This is a total abuse of power,” he said. “No politician should have that type of power.”

Mr. Oberlander's case dates back to 1995, when the government first announced its intention to revoke his citizenship and deport him. The 83-year-old former developer from Waterloo has fought the case ever since.

Human rights lawyer David Matas once described him as “the poster child for delays.”

The government first went after Mr. Fast -- now in his mid-90s and suffering from Alzheimer's -- in 1999.

Justice Minister Rob Nicholson said due process was followed.

“It is now time to move forward,” he said.

He said the government takes war crimes cases seriously.

“Canada will not become a safe haven for anyone who has been involved in war crimes, crimes against humanity or genocide.”

Mr. Oberlander and Mr. Fast can still ask the Federal Court to decide if the cabinet action was lawful, but cannot challenge the earlier findings of fact in their cases.

Bernie Farber of the Canadian Jewish Congress welcomed the cabinet decision.

“It's been a long time coming,” he said.

Mr. Farber said the decision goes beyond these two cases.

“They've sent a strong message to those who today are engaged in war criminal activities, whether it's in Dafur or any other country,” he said. “The government today, by acting on Oberlander and Fast, have basically now slammed the door on any others who would want to see Canada as a safe haven.”

“That's no longer in the cards, so this is good for everybody.

Three other cases involving Nazi collaborators remain in the system and Mr. Farber said he hopes they will be concluded quickly.

Since 1977, Canada has stripped 54 people of their citizenship, although only seven of those cases related to the Second World War.