It was the threat of gang violence in Honduras that pushed Carlos and Antonia to flee their home. In 2021, with their toddler, Alejandro, and a handful of belongings, the married couple ventured north hoping to reach safety in the US.

The journey, through Guatemala and Mexico, was filled with danger and uncertainty

“We were in constant fear, every time we had to cross the border and travel with a young child,” said Antonia. “We were terrified.”

Arriving as the US began Donald Trump’s migration purge, their opportunity to make an asylum claim vanished. A lawyer advised them if they appealed, they risked being detained at their migration hearing and deported.

Because Carlos has family members in Canada, they pushed farther north. But their arrival at the Fort Erie border crossing did not end of their precarious journey.

A Canadian border agent said he would let Carlos and Alejandro in, but Antonia – who did not have family in Canada – would be sent back to the US. Or all three could return to the US and risk detention and deportation.

“[I said]: ‘What am I supposed to tell my son about why they’re not going to let his mother come in with us?’ And the border officer just said, ‘That’s your problem, you’ve got 20 minutes to make a decision,’” Carlos later recalled.

Antonia began crying. “There was no way I could be separated from my son. I was completely in shock,” she later said. “And then my son started crying, too.”

The family, whose names have been changed for safety, opted to stay together. They were sent back to the US – and then deported to Honduras.

Their story is central to a court challenge by the Canadian Council for Refugees, Amnesty International Canada and the three Hondurans, which argues that Canadian border officials are failing to uphold court-ordered safeguards for asylum seekers before turning them back to the US under the Safe Third Country Agreement.

Until 2004, asylum claims could be made at any legal port of entry in Canada, where they would then be processed and claimants admitted if their claim was approved.

That changed when Ottawa successfully lobbied for the passage of the Safe Third Country Agreement (STCA), forcing migrants to make asylum claims in the country where they first arrived. It initially applied to land-based ports of entry – but not to irregular or unofficial crossings.

But advocacy groups and legal experts increasingly argue that the US should not be considered a safe third country. They point to the country’s long-term detention of those seeking refuge and threats to deport asylum seekers to countries where they could be harmed or killed.

At the same time, Canada is also tightening its own asylum system. New legislation has created further ineligibility rules for refugee claimants, prompting critics to accuse Mark Carney’s government of introducing “Trump-style” immigration policies.

Carlos, Antonia and Alejandro – who is now six years old – have gone into hiding in Honduras, over fears of retribution from the same gang they fled.

In 2023, Canada’s top court ruled the STCA was constitutional, ending a lengthy legal challenge by advocacy groups such as the Canadian Council for Refugees and Amnesty International Canada, which have long argued the deal violates the rights of asylum seekers. But in its judgment, the court also found that the inclusion of legislative “safety valves” in the agreement, including the discretion to exempt someone from returning to the US on the basis of humanitarian and compassionate grounds, meant the rules align with “the principles of fundamental justice”.

Advocacy groups say those “safety valves” only exist in theory, citing the growing number of asylum seekers sent by Canadian authorities to detention in the US.

“Every day, people fleeing danger present themselves at the Canadian border expressing grave fears about what will happen to them if they are returned to the US,” Asma Faizi, president of the Canadian Council for Refugees, said in a statement. “While their fears are very real, the ‘safety valves’ supposedly offered by the Canadian government do not in practice exist and refugees’ pleas for protection are ignored.”

In court documents, those groups point out that asylum seekers are typically not told they can seek an exemption or give evidence. Instead, often without access to legal counsel, they must make a quick decision that will define their lives for decades to come.

Canada’s border agency said in a statement that officers have limited discretion in “exceptional cases only” to delay a removal. A claimant must demonstrate clear and credible evidence they would face death, inhumane treatment or the threat of deportation without due process if sent to the US.

But Canada’s federal government has defended the US, saying it continues to meet the legal requirements under the agreement to remain a safe third country. The allegations of the claimants have not been tested in court. A judge must first decide whether to grant leave before the challenge can proceed.

“We wish we could show our faces and shout to the world and let everyone know that this is what happened to us. It is just not safe for us. But we are doing what we can to fight this,” said Carlos.

“The hardest thing has been trying to explain this all to our son. From one day to the next, everything was turned upside down for him: his world, his community, his space. It’s not easy for a child to compartmentalize. It’s not easy for an adult either.”