Saudi Arabia's apparent deployment of made-in-Canada combat vehicles against its own citizens last week is breathing new life into a legal challenge of the Canadian government's $15-billion arms deal with Riyadh.

Daniel Turp, a University of Montreal professor who took the Trudeau government to court last year, has written Foreign Affairs Minister Chrystia Freeland saying he will forge ahead with a renewed effort to block combat vehicle exports to Saudi Arabia unless she takes action.

In January, the Federal Court rejected Mr. Turp's bid to stop the export of $15-billion in weaponized armoured vehicles to Saudi Arabia, a country with an abysmal human-rights record. The Trudeau government approved export permits for these machines in April, 2016, a deal brokered by Ottawa that officials have boasted is the largest advanced manufacturing export transaction on record. The light-armoured vehicles made by General Dynamics in London, Ont., are being equipped with machine guns or anti-tank weapons.

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In her January, 2017, decision, Justice Danièle Tremblay-Lamer noted that Mr. Turp had not produced evidence demonstrating that Canadian-made combat machines had been used to oppress Saudi citizens.

"For there to be a reasonable risk, there must at least be some connection between Saudi Arabia's alleged human-rights violations and the use of the exported goods," Justice Tremblay-Lamer wrote.

Mr. Turp argues that what the federal judge was looking for is now available – given that video footage and photos have emerged from Saudia Arabia's Eastern Province showing what appear to be armoured vehicles, with gun turrets, made by Terradyne Armored Vehicles of Newmarket, Ont.

"It's impossible for them to argue any more that there is no reasonable risk," he said.

Last week, Ms. Freeland responded to Globe and Mail reports of Terradyne vehicles being deployed against Shia militants in Saudi Arabia's Eastern Province by saying she was "deeply concerned," and launching a probe of the matter. She said she would take action if Canadian equipment was being used to oppress Saudis.

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While Canadian political debate over the past 18 months has focused on a landmark $15-billion deal to supply Riyadh with General Dynamics light-armoured vehicles, other Canadian armoured-vehicle makers such as Terradyne have been making separate defence sales to the Saudis.

Lawyers for Mr. Turp sent Ms. Freeland a letter this week urging her to revoke export permits for the $15-billion General Dynamics deal, noting that former foreign affairs minister Stéphane Dion had said he would suspend or cancel permits if Canadian armoured vehicles were found to be repressing Saudi citizens.

"Your predecessor had formally committed to reconsider its decision to issue export permits or to revoke these permits, if evidence was provided to him," the letter from law firm Trudel Johnston & Lespérance said.

"We therefore urge you to reconsider your predecessor's decision and immediately cancel the export licenses issued by Mr. Dion … If we do not receive a favourable response from you by September 5, we will have no choice but to undertake the necessary judicial proceedings to enforce your obligations as Foreign Under the Export and Import Permits Act and the Geneva Conventions."

Mr. Turp has an appeal of the Federal Court's January decision under way – which he says could be heard as early as September – and is considering whether to launch a second lawsuit based on the Terradyne case.

In 2016, The Globe and Mail published videos supplied by human-rights activists showing Saudi armoured vehicles being deployed against Shia Muslim citizens. While the footage demonstrated Riyadh's proclivity to use such machines against its own people, the Trudeau government dismissed the evidence as irrelevant because the military equipment in those cases wasn't Canadian-made.

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Last week marked the first time videos and photos have surfaced allegedly showing the Saudis wielding Canadian-made defence equipment against their own people. The House of Saud's apparent use of Canadian combat machines against its Shia population in eastern Saudi Arabia goes to the heart of a long-running controversy over whether the Trudeau government is violating Canada's weapons export-control rules.

These rules call for restrictions on arms exports to countries with a "persistent record of serious violations of the human rights of their citizens." Shipments are supposed to be blocked if there is a real risk the buyer could turn arms against its own population.