Department of Justice refuses to provide evidence in Order in Council case

The federal government continues to introduce obstacles in its court case to uphold last May's Order in Council gun bans. Now, the Department of Justice is invoking Section 39 of the Canada Evidence Act to avoid handing over information to the judge in the case—information the feds supposedly used to determine which firearms to ban.
This story is just the latest twist in the federal government's Order in Council (OIC) firearms bans, enacted in May, 2020. At that time, the Trudeau Liberals announced bans on dozens of hunting, sporting and tactical firearms, adding more as the year went on. The ban was announced via Order in Council, with no parliamentary debate.
Firearms owners were understandably unhappy with the prospect of arbitrarily losing their firearms, without having committed any crimes. The OIC process was filled with errors, and law enforcement deemed it a waste of government resources.
So, Canada's firearms owners went to court. There are several legal battles ongoing around the country, attacking the OIC bans from various angles. One of the biggest court cases sees a group led by the Canadian Coalition for Firearms Rights (CCFR) scrapping with the Attorney General of Canada (Court File No. T-577-20).
The CCFR saw an early setback in this case, when its application for an injunction against the OIC (to delay its implementation while the court case worked itself out) was denied.
However, the CCFR and its associated parties caught a break at the end of May. Then, Associate Chief Justice Jocelyne Gagné gave the Attorney General of Canada 30 days to provide documents that served as the basis for the federal government’s gun ban position. The Department of Justice previously hid this information, citing cabinet privilege.  Upon receiving the documents, the judge would determine if they qualified for cabinet confidence, or if “public interest in disclosure outweighs its secrecy.”

Where we're at now

Now, the federal government is fighting back against that ruling, using another tactic to hide its reasoning behind the OIC. Here's what the CCFR's website has to say:

Bruce Hughson of the Department of Justice forwarded a notice to the Federal Court concerning our case against the Attorney General of Canada. The notice is to inform the court that the government has invoked Section 39 of the Canada Evidence Act. This is an action that the Clerk of the Privy Council can take to "make secret" any materials the government doesn't want the public to see. This puts the materials, in this case the government's evidence, beyond the reach of anyone, even the courts. Supposedly, this sweeping power is exercised when the material is so sensitive, it is against the public interest to disclose it. 

You can see more here, but in summary: The Department of Justice says the information behind last May's firearms ban is so sensitive that the public doesn't need to know it, and the courts can't even be trusted with it.
Will this play work out for the feds? Maybe, maybe not, but it seems likely Judge Gagné will be unimpressed with the move. This introduces even more delay, and reinforces the thesis that the Department of Justice is simply trying to run out the clock with this legal battle, allowing gun seizures to begin before the case is resolved.