“The Government has shown that it is very likely to prevail when this question is ultimately decided,” Justice Samuel Alito wrote, joined by Justices Neil Gorsuch and Brett Kavanaugh.

While the three signaled they viewed the prisoners’ claim as a weak one, Alito said it would be best to allow the current challenge to play out now rather than wait until after the men are put to death.

“In light of what is at stake, it would be preferable for the District Court’s decision to be reviewed on the merits by the Court of Appeals for the District of Columbia Circuit before the executions are carried out,” Alito wrote.

The broader court offered no rationale for turning down the Justice Department’s request to proceed with the executions as scheduled, but did release a single line urging the D.C. Circuit to act quickly.

“We expect that the Court of Appeals will render its decision with appropriate dispatch,” the high court’s order said.

Justice Department spokeswoman Kerri Kupec expressed regret about the setback but said officials would press on to remove any roadblocks to the executions.

“While we are disappointed with the ruling, we will argue the case on its merits in the D.C. Circuit and, if necessary, the Supreme Court,” Kupec said. “The Department of Justice is committed to upholding the rule of law and to carrying forward sentences imposed by our justice system.”

Last month, Washington-based U.S. District Court Judge Tanya Chutkan blocked four of five executions Attorney General Bill Barr announced in July. Chutkan said the death row inmates appeared likely to prevail on their claims that the so-called protocol announced to execute the men by lethal injection did not adhere to the procedures used by individual states where they were convicted.

The execution of a fifth inmate was blocked by the 9th Circuit Court of Appeals on other grounds.

On Thursday, a federal judge in Indiana issued a reprieve to the first federal prisoner schedule to die next week, Daniel Lee. Lee was convicted in 1999 of killing three members of an Arkansas family—Nancy Mueller, William Mueller and 8-year-old Sarah Powell— as part of a white supremacist plot.

A federal appeals court panel in Chicago lifted that stay just before the Supreme Court ruled Friday, but Lee’s execution remains on hold due to Chutkan’s decision.

Shawn Nolan, one of the attorneys for the men facing federal execution, said in a statement: "Three courts have now agreed that the federal government’s new execution protocol must be fully adjudicated before it can be used to carry out executions. The courts have made clear that the government cannot rush executions in order to evade judicial review of the legality and constitutionality of its new execution procedure.”

The vast majority of executions in the U.S. take place at the state level, but there are about 60 prisoners on federal death row. The last execution in the federal system was in 2003.