Drivers wait to cross through Canadian customs at the Canada-US border near the Peace Arch Provincial Park in Surrey, British Columbia, Canada. Canada March 16, 2020.
Drivers wait to cross through Canadian customs at the Canada-US border near the Peace Arch Provincial Park in Surrey, British Columbia, Canada. Canada March 16, 2020. Reuters / Jesse Winter

The agreement under which Canada turns back asylum-seekers crossing from the United States has adequate safety valves, and the U.S. asylum system has sufficient safeguards, to make the pact constitutional in Canada, the federal government argued in court documents filed with Canada's Supreme Court on Wednesday.

Under the Safe Third Country Agreement, signed in 2002, asylum-seekers crossing the Canada-U.S. border at formal crossings are turned back, with few exceptions, and told to apply for refugee status in the first "safe" country they arrived in.

"It does not shock the conscience to require claimants who entered the United States first to return to pursue their claims there," Canada's argument reads.

The agreement is reasonable and within the Canadian government's powers and the designation of the United States as a "safe" country remains reasonable, the government states.

Canadian courts have twice found the agreement unconstitutional and twice appeals courts have overturned these rulings. This is the first time the agreement will go to Canada's Supreme Court.

Refugee advocates in Canada argue that the agreement violates asylum-seekers' Charter rights to life, liberty and security of the person and to equal treatment. They argue the U.S. system is not analogous to Canada's and that people turned back under the agreement may be detained indefinitely and deported even if they might have had a shot at refugee status in Canada.

Meantime, Canada has been pushing the United States to expand the agreement so it applies the full length of the border, rather than just at formal crossings.

Now, asylum-seekers can enter Canada between ports of entry, such as at Roxham Road in Quebec, and file refugee claims. The number of people doing so this winter reached numbers not seen since the summer of 2017.