The Conservative government was poised to introduce a new law constraining a federal spy agency's ability to warrantlessly intercept some Canadian communications – until that bid was derailed amid controversies over unrelated legislation.

Legal fixes for Communications Security Establishment Canada, Ottawa's electronic intelligence agency, had been considered "a legislative priority" by the Tories five years ago, to the point that then-defence minister Peter MacKay was successfully pushing for a package of amendments at the cabinet table.

These fixes were regarded as necessary because two former Supreme Court justices had highlighted the spy agency's laws as flawed. So had other retired judges who had also left their courtrooms to serve as CSEC's watchdog "commissioner."

Story continues below advertisement

During the past year, controversies surrounding the spy agency have prompted two Liberal MPs to introduce private member's bills for improved oversight. Last week, in a letter obtained by The Globe and Mail, they wrote Defence Minister Rob Nicholson, pressing for urgent change.

Yet the Conservatives' years-earlier proposals for reform – which never materialized in Parliament – appear to have been moved back indefinitely.

"We are aware of recommendations to amend the National Defence Act but will not speculate on possible future legislative amendments," wrote Julie Di Mambro, a spokeswoman for Mr. Nicholson, in reply to Globe questions. (The office of Mr. MacKay, now Justice Minister, declined comment.)

The bid to reform CSEC's laws had been quietly building momentum within government, until an unrelated police-surveillance bill, C-30, was tabled and proved deeply unpopular. (Former public safety minister Vic Toews leached support away from that act with his polarizing remark that the Opposition "can either stand with us or with the child pornographers.")

Surveillance legislation had been an easier sell in Parliament after the attacks of Sept. 11, 2001. That year, a few overlooked clauses in the omnibus Anti-Terrorism Act gave rise to what amounts to a get-out-of-jail-free-card to CSEC, which was then a relatively obscure "foreign intelligence" agency.

It is a crime for federal agents to snoop on Canadian private communications without a judge's permission, yet the "ministerial authorization" power put on the books for CSEC in 2001 gave the agency unique leeway. In exceptional cases, the minister can unilaterally authorize the spy agency to "incidentally" intercept and keep some Canadian conversations and e-mails, without warrants, if it is felt that those communications can point to designated "foreign-intelligence" targets in the wider world.

But the specific authorizations and target lists are secret documents. And for nearly a decade the judges running CSEC's watchdog body have said the defence minister and the spy agency are interpreting these last-resort powers in a way that the law does not support.

Story continues below advertisement

The issue revolves around how to define intelligence targets. After the Anti-Terrorism Act passed, intelligence officials often explained that a CSEC analyst could be allowed to listen in on what was said if Osama bin Laden called a Canadian – whereas before the analyst would have risked jail for failing to hang up.

Yet the watchdog agency has long expressed fears the power has never been interpreted as discriminatingly as that example would indicate.

Details are classified. But the distinction may amount to the difference between the minister telling CSEC to go after "Osama bin Laden" – and telling it to go after "terrorists." The specific language would reduce or increase the number of Canadian phone conversations or e-mails that CSEC could catch collaterally.

The spy agency's leadership – which points out that it has never been found to have acted unlawfully – has said the numbers of private communications captured in this way are "small," or "very small." But the watchdog judges have not been reassured. For years they have said the law doesn't square with CSEC's expansive reading of it – yet the watchdog is prepared to adopt it as an "interim" measure, until Parliament fixes the problem.

Former Supreme Court justice Charles Gonthier highlighted the issue when he served as the watchdog in the late 2000s. "CSEC and my office are still on opposite pages," he wrote in 2008, before adding that his spirits were buoyed by "pending legislation." Two years later, he wrote that he had been "informed by the Minister of National Defence [Mr. MacKay] that clarification of ambiguities … are a legislative priority."

Unlike allied agencies in the United States and United Kingdom, CSEC is never directly scrutinized by sitting judges or legislators – the people who have the power to interpret, craft and enforce laws in binding ways.

Story continues below advertisement

Instead, the only direct check on CSEC is the watchdog commissioner, the top court justice who finds himself heading an advisory body sitting firmly within the executive branches of government.

"For jurists who are accustomed to dealing with warrants issued by judges, a foreign intelligence MA [ministerial authorization] is a strange sort of creature," retired Supreme Court chief justice Antonio Lamer wrote in an annual report.

Serving as CSEC Commissioner in the mid-2000s, he said that his one regret when he retired was not solving "the legal interpretation issues that have bedevilled this office since December 2001" – the date the Anti-Terrorism Act passed.