A federal judge on Wednesday declared Homeland Security’s expansive policy letting him send illegal immigrants to so-called third countries is illegal, in a decision that could blow a hole in the president’s mass deportation efforts.

U.S. District Judge Brian Murphy, a Biden appointee and frequent legal opponent of President Trump, said DHS’ policy doesn’t give migrants enough chance to challenge their deportations when they’re sent to third countries where they have never lived.

“It is not fine, nor is it legal,” the judge wrote.

He stayed the effect of his ruling for 15 days to give the administration a chance to appeal.

Judge Murphy’s previous orders in the case have been blocked by the Supreme Court, and it’s likely this latest decision will race to the justices as well.

Third-country removals come when someone’s home country is unwilling to take him or her back or when a U.S. official has determined a migrant cannot be safely sent back.

They occurred in years past but were relatively rare.

The Trump administration, however, has made them a tentpole of its deportation policy, hoping to cut into the backlog of tens of thousands of people who have been ordered out of the country but who remain because of obstacles in their home nations.

Judge Murphy, who sits in Massachusetts, acknowledged the law allows for third-country removals but said the Constitution requires a fair chance for migrants to challenge the specific removal. He said DHS’ policy short-changes that.

He pointed to one of the plaintiffs, a Guatemalan man known in court documents by the initials OCG. He faced sexual violence in Guatemala, came to the U.S. illegally and was ordered deported, but the immigration judge said he couldn’t be sent there because of the chance he’d be victimized again.

So the U.S. sent him to a third country, Mexico, where he was in fact raped — then Mexico deported him to Guatemala anyway.

And the government “lied about it,” the judge scolded.

The Washington Times has sought comment from DHS.

Judge Murphy first tangled with the Trump administration over third-country deportations last year, saying they deserved more due process. He also issued an order to halt a deportation of eight migrants being sent to South Sudan rather than their home nations.

They ended up living in a shipping container at a U.S. military base in Africa’s Djibouti while the case developed.

The Supreme Court blocked both of those rulings.

Judge Murphy, in his new ruling, said the law pushes for a deportee to choose his destination, but when that country won’t take him, the U.S. can search for alternatives. He said the law’s goal is to maximize the migrant’s choice and safety.

DHS’ new policy, he said, doesn’t give the migrants’ preferences enough weight.

He said the government’s position appeared to be that it can send someone to a country with no notice and no opportunity to object, as long as U.S. officials don’t know of an immediate threat to the migrant’s life.

The most prominent third-country removals carried out by the Trump administration involved Venezuelans whom the government designated as gang suspects last March and shipped to El Salvador’s terrorism prison.

After a legal battle, they were released to Venezuela in a prisoner swap with El Salvador.