Eight migrants in United States custody have lost a last-ditch attempt to avoid deportation to South Sudan, a country facing ongoing criticism for human rights abuses.

On Friday, Judge Brian Murphy of Boston denied the eleventh-hour appeal, which has been the subject of a flurry of legal activity throughout the day.

The appeal argued that repeated efforts under President Donald Trump to deport the men to South Sudan was “impermissibly punitive”. It pointed out that the US Constitution bars “cruel and unusual punishment”.

In the past, the US Department of State has accused South Sudan of “extrajudicial killings, forced disappearances, torture and cases of cruel, inhuman and degrading treatment or punishment”. It advises no American citizen to travel there due to an ongoing armed conflict.

But the US Supreme Court has twice ruled that the Trump administration could indeed deport the men to countries outside of their homelands. Its latest decision was issued on Thursday.

The US Department of Justice indicated that the eight men were set to be flown to South Sudan by 7pm US Eastern Time (23:00 GMT) on Friday. They hailed from countries like Cuba, Laos, Mexico, Myanmar, Sudan and Vietnam.

The last-ditch appeal was filed on Thursday night, shortly after the Supreme Court rendered its decision.

Initially, the case was assigned to US District Judge Randolph Moss in Washington, DC, who signalled he was sympathetic to the deportees’ request.

He briefly ordered the deportation to be paused until 4:30pm Eastern Time (20:30 GMT), but ultimately, he decided to transfer the case back to Murphy, the judge whose decisions helped precipitate the Supreme Court’s rulings.

Murphy had previously issued injunctions against the deportations to South Sudan, leading to successful appeals from the Trump administration. The eight men, meanwhile, had been held at a military base in Djibouti while the courts decided their fate.

Before he transferred the case back to Murphy, however, Judge Moss said it was possible the deportees could prove their case that the Trump administration intended to subject them to abuse.

“It seems to me almost self-evident that the United States government cannot take human beings and send them to circumstances in which their physical wellbeing is at risk simply either to punish them or send a signal to others,” Moss said during the hearing.

Lawyers for the Trump administration, meanwhile, argued that the deportation’s continued delay would strain relations with countries willing to accept migrants from other countries.

Murphy, who denied Friday’s request, had previously ruled in favour of the deportees, issuing an injunction against their removal to South Sudan and saying they had a right to contest the deportation based on fears for their safety.

The Supreme Court first lifted the injunction on June 23 and clarified its ruling again on Thursday, giving a subtle rebuke to Judge Murphy.

The Trump administration has been pushing for rapid removals as part of its campaign of mass deportation, one of President Trump’s signature priorities.

Opponents have accused the administration of steamrolling the human rights of undocumented people in order to achieve its aims, including the right to due process under the law.

But the Trump administration has framed undocumented migration as an “invasion” that constitutes a national security crisis, and it argued that its strong-armed efforts are needed to expel criminals.

The eight migrants slated to be sent to South Sudan, it said, were “barbaric, violent criminal illegal aliens”. It added that they had been found guilty of crimes, including first-degree murder, robbery and sexual assault.

“These sickos will be in South Sudan by Independence Day,” Homeland Security spokesperson Tricia McLaughlin said in a news release on Thursday.