OTTAWA - Canada's controversial national security-certificate system faces a new constitutional challenge from Mohamed Harkat -- one month after a court declared the Ottawa man a danger to the country.

Lawyers for Harkat, who is accused of links to terrorists, want the Federal Court of Appeal to determine whether the security certificate being used to deport him is consistent with the Charter of Rights and Freedoms.

It is one of several questions they're asking Judge Simon Noel, who heard the original case, to approve for examination.

Harkat, a former gas attendant and pizza delivery man, was arrested more than eight years ago under a security certificate on suspicion of being an al Qaeda sleeper agent. He denies any involvement in terrorism.

Harkat, 42, says he's merely a refugee who fled strife-torn Algeria and worked with an aid agency in Pakistan before coming to Canada. He argues he will be tortured if returned to his homeland.

In his December ruling, Noel called Harkat a security threat who maintained ties to Osama bin Laden's terror network, including Ahmed Said Khadr -- the late father of Toronto's Omar Khadr, who has spent years in a U.S. prison at Guantanamo Bay, Cuba.

Noel found Harkat's testimony in the certificate case to be incoherent and implausible at times.

In a companion judgment, the judge upheld the constitutionality of the security certificate system -- a seldom-used tool for removing non-citizens suspected of terrorism or espionage.

The government revamped the certificate process after the Supreme Court of Canada declared it unconstitutional in 2007. A key change was the addition of special advocates -- lawyers who serve as watchdogs and test federal evidence against the person facing deportation.

However, the special advocates do their work behind closed doors due to the sensitive nature of the classified information before the court in such cases.

Harkat's lawyers say much of the evidence Noel consulted in weighing the validity of the certificate against Harkat remains secret and has never been tested through cross-examination.

In documents filed with the Federal Court, counsel for Harkat cite arguments including:

  • The court cannot base its decision on fact and law when the named person is provided with only a summary of the case.
  • The refusal to disclose information due to national security concerns violates the principles of fundamental justice.
  • The provision of special advocates fails to ensure the process is constitutional.

"The issues raised by these questions are centrally relevant to all security certificate matters and thus transcend the interests of Mr. Harkat," says the court filing.

The lawyers also want the appeal court to look at the judge's fact-finding based on open sources, the court's approach to assessing evidence and the definition of terrorism, among other matters.

The government will reply to the arguments before Noel decides whether to put some, all or none of the questions before the Federal Court of Appeal.

Harkat, who lives with his wife in Ottawa, remains on bail under strict conditions that require him to wear an electronic tracking bracelet on his ankle.