Foreign Affairs Minister Stephane Dion is defending his decision to sign the export permits for the Saudi Arabia arms deal, saying there is no evidence the Canadian-built light armoured vehicles will be inappropriately used by the desert kingdom.

Dion came under fire for quietly approving the export of $11 billion worth of LAV3s – the bulk of the nearly $15-billion deal with Saudi Arabia. According to documents released to The Canadian Press, government officials advised Dion that they were satisfied the Saudis would not use the combat vehicles against their own citizens.

The Liberals have long said that they couldn’t cancel a deal that was already negotiated and approved by the previous Conservative government. However, the presence of Dion’s signature on the export permits put that claim into question.

Dion told reporters on Parliament Hill Wednesday that cancelling the Saudi arms deal would "weaken the credibility of the signature" of the government of Canada and affect about 2,000 jobs in London, Ont.

If at any time the government receives credible information that Saudi Arabia is violating the terms of the LAV3 deal, Dion said he will revoke the export permits.

"For the future, as with all exports permits, the minister of foreign affairs retains the power to revoke, at any time, the permit should the assessment change," said Dion.

"Should I become aware of credible information of violations related to this equipment, I will suspend or revoke the permits."

Ottawa is also defending the deal by saying it has sold thousands of LAVs to the Saudis since the 1990s, and more than 1,300 sniper rifles.

The Liberals have been strongly criticized for not cancelling the arms deal, on account of Saudi Arabia’s treatment of women, religious minorities, activists, and prisoners.

But they have said they made a commitment not to cancel private contracts, and have ensured that the LAV3s will be “properly used."

Prime Minister Justin Trudeau told the House of Commons Wednesday that the Liberals have maintained their stance on the deal since the election last October.

"We will honour the contracts signed by Canada in February 2014," said Trudeau.

"The fact is, there are jobs in London relying on this (and) there are commitments made to the world that we will honour our good name when sign our contracts."

NDP Leader Tom Mulcair responded by saying Canada's reputation is also built on its history of "standing up to defend human rights around the world."

In an appearance on CTV's Power Play, NDP MP Nathan Cullen questioned Dion's ability to monitor for human rights abuses.

"If the idea is that somehow Stephan Dion is going to be (monitoring) when the Saudis are committing human rights atrocities -- that’s going to be the check that Canada has -- or that we're going to somehow send observers to follow these vehicles around to make sure they're not oppressing Saudis or other minority groups in Saudi Arabia, (that) is insane," he said.

Daniel Turp, a law professor at University de Montreal, and his students filed a judicial review in Federal Court last month seeking to block the arms deal.

Appearing on Power Play Wednesday, Turp said it was "very surprising" to learn that Dion had signed the exports permits last week.

"No one heard about it and there was nothing in the papers, on TV or radio Saturday, or the beginning of week, so it was a really astonishing that this decision was taken and not made public," said Turp.

"There is a case in front of the federal government now, and what was the strategy: to do something so the judge couldn’t decide on the basis of our action?" he added.

Turp said the case is all about human rights.

"Human rights should be at the centre of foreign policy and you shouldn’t trade arms with countries that have the worst record on the planet when it comes to human rights, and that's Saudi Arabia," he said.

He added the stipulation that the deal will be cancelled should Saudi Arabia violate any human rights is not enough.

"That will be too little too late, because human rights would have breached," said Turp

"There shouldn’t have been a contract and these export permits shouldn’t have been delivered last Friday."

Turp said the case will go on, and his lawyer and the attorney general are set to meet Thursday with the judge.

He said a "judge will hear this case," and if need be, his group will amend their action so a court can declare the exports permits illegal.

"I think there is a strong case that there are risks, and if you sell arms of such nature to Saudi Arabia they could be used to breach human rights," said Turp.