The federal government's anti-terrorism legislation is not a threat to civil liberties, a senior Justice Department official argued Thursday.

Richard Mosley, who oversaw the initial draft of Bill C-36, made the comments during a briefing with journalists.

One of the contentious proposals allows the minister of justice to suspend the Access to Information Act in the name of national security and international relations.

Canada must be able to keep some matters secret if it's to be taken seriously by allies, Mosley said especially now that U.S. and British anti-terrorism measures include similar powers.

"They can protect their secrets," Mosley pointed out. "If we can't, they won't share them with us. And if they don't share them with us we're not going to be able to use that information in the pursuit and protection of national security."

Power won't be abused by ministers, he argued, because it would hurt their chances of being re-elected.

Justice Minister Anne McLellan has said the government is willing to amend the bill, which is being reviewed by a Commons committee. Next week, she is expected to outline the changes that cabinet is prepared to make.

A group of senators has already recommended a sunset clause be included so that the new extraordinary powers given to spies and police investigators are reviewed within five years.