The Trump administration moved Thursday to revive the federal death penalty, a policy move Congress has not tried to prevent but one that will face a legal challenge from civil rights groups.

Attorney General William Barr directed the Bureau of Prisons to adopt a new execution protocol — which would kill inmates with an injection of a single lethal drug called pentobarbital — and schedule the execution of five men in December and January.

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Those would be the first executions by the federal government since 2003. The move comes as public support and the use of the death penalty by states has waned because of moral concerns, questions about execution protocols and death row exonerations through the use of DNA and other new evidence techniques.

Barr said in a news release that Congress authorized the death penalty and the Justice Department has sought to use it against the worst criminals. “The Justice Department upholds the rule of law — and we owe it to the victims and their families to carry forward the sentence imposed by our justice system,” Barr said.

Democratic lawmakers filed legislation to abolish the federal death penalty year after year since the turn of the century, but that appears to have ended in the 113th Congress. Back then, the bill introduced by Maryland Democratic Rep. Donna Edwards to strip the death penalty provisions from a wide range of criminal offenses, had 13 cosponsors but died in committee.

This session, the only bill to mention the death penalty  from Rep. Vern Buchanan seeks to expand the list of aggravating factors prosecutors can consider when deciding to pursue the death penalty against those charged with killing or targeting law enforcement officers or first responders.

A longstanding legal challenge to the old federal lethal injection protocol from death row inmates, along with a lack of availability of the drugs needed for it, kept the government from conducting executions for years, said Ruth Friedman, director of the Federal Capital Habeas Project that helps represent federal death row defendants.

The government repeatedly updated the judge in that litigation that it was working on a new protocol, and the Trump administration filed a notice Thursday of the new protocol.

But the Trump administration also on Thursday set the executions of the five death row inmates who are not part of that challenge, and the government did not go through the federal rule-making process for this new protocol — something Friedman called a “calculated attempt” to avoid scrutiny of the protocol.

The first execution on Dec. 9 would be Daniel Lewis Lee, a member of a white supremacist group who murdered a family of three, including an 8-year-old girl in Arkansas, DOJ said. The fourth would be Alfred Bourgeois, who physically and emotionally tortured, sexually molested and then beat to death his 2-year-old daughter.

The American Civil Liberties Union announced Thursday it was consulting with a broad coalition of groups and would challenge the policy.

“Under no circumstances should the Justice Department be allowed to rush through executions,” said Cassandra Stubbs, director of the ACLU’s Capital Punishment Project. “The federal death penalty is defined by the same problems of racial bias, geographic disparities, prosecutorial misconduct, and junk science that have led to the decline in support for capital punishment nationwide.”

Since the reinstatement of the federal death penalty in 1988, 78 defendants have been sentenced to death, according to the Death Penalty Information Center, or DPIC. Three have been executed — including Oklahoma City bomber Timothy McVeigh in 2001 — and 12 defendants have been removed from death row. The last execution was Louis Jones in 2003 for the kidnap and murder of a female soldier in Texas.

Lawyers for death row inmates have filed numerous challenges over the decades to lethal injection protocols — many that use a three-drug process — and whether they violate the Eighth Amendment’s prohibition on cruel and unusual punishment.

The Supreme Court also has vigorously debated in recent years how the ultimate penalty is meted out in the United States, but continues to uphold the death penalty as constitutional.

Five states have used the new federal procedure, the single-drug pentobarbital method, for 125 executions — 22 in Georgia, one in Idaho, 20 in Missouri, three in South Dakota, and 79 in Texas, according to DPIC.

But it hasn’t always been easy for states to obtain pentobarbital, a drug veterinarians use to euthanize animals, because the European manufacturer won’t sell it for human execution. Some states and death penalty advocates have wanted Congress to act to secure a supply for states.

When Texas obtained a supply of pentobarbital in 2015, state officials refused to identify the pharmacy that provided it because of threats of violence from anti-death penalty groups. Missouri turned to a compounding pharmacist for the pentobarbital used in a 2013 execution but that can bring unwanted criticism to the suppliers.

When the court first upheld lethal injection, the anesthetic in the three-drug cocktail was sodium thiopental. But the manufacturer stopped supplying it for executions in 2011.

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There is political pressure as well. Pope Francis told lawmakers in a joint address to Congress in 2015 that he had long advocated for “the global abolition of the death penalty.”

Pennsylvania’s governor put a moratorium on executions in 2015, saying flaws in the system make it “error prone, expensive, and anything but infallible.”

A 2018 survey by Pew Research Center found support for the death penalty had a slight uptick, with 54 percent of Americans saying they favored the death penalty for people convicted of murder, up from 49 percent in 2016.

Pew also found the question sharply divided on political lines, as around three-quarters of Republicans said they supported the death penalty for those convicted of murder, while a majority of Democrats said they opposed it.

The Justice Department released statistics Wednesday that the national death row population decreased for the 17th year in a row, with declines in Florida and Delaware coinciding with court rulings that found capital sentencing procedures in those states unconstitutional, according to DPIC.

The number of state and federal death sentences per year in the country has dropped dramatically from 1998, when 295 people were put on death row, to 2018, when 43 people were, DPIC said.

Sen. Dianne Feinstein of California, the top Democrat on the Senate Judiciary Committee, cited racial disparity in death row executions and exonerations as reason why 21 states currently outlaw the death penalty and “it’s time for the federal government to catch up.”

There have been more than 160 death row exonerations since 1973, Feinstein said in a news release.

“You can’t fix an improperly implemented death penalty,” Feinstein said. “The federal government should be leading the effort to end this brutal and often cruel punishment, not advocating for its return. It’s time we evolve and put this terrible practice behind us.”