Attorney General William P. Barr on Monday directed federal prosecutors across the country to “be on the lookout” for state and local coronavirus-related restrictions that might run afoul of the Constitution and to pursue court action, if necessary.

In two-page memo to U.S. attorneys across the country, Barr wrote that the measures state and local government officials had taken “have been necessary in order to stop the spread of a deadly disease,” but even in times of emergency, the Constitution could not be discounted entirely.

“Now, I am directing each of our United States Attorneys to also be on the lookout for state and local directives that could be violating the constitutional rights and civil liberties of individual citizens,” Barr wrote, adding later, “If a state or local ordinance crosses the line from an appropriate exercise of authority to stop the spread of COVID-19 into an overbearing infringement of constitutional and statutory protections, the Department of Justice may have an obligation to address that overreach in federal court.”

Many states and localities have commanded residents to stay at home, except for essential trips for food and other supplies, and issued other directives meant to stem the spread of covid-19, the potentially fatal respiratory disease caused by the coronavirus. Barr’s memo did not cite specific policies he found objectionable. Justice Department officials have said in recent weeks that Barr is not looking to roll back reasonable restrictions and force the opening of the country, but rather, to encourage officials to carefully weigh the necessity of what they are doing.

President Trump has pushed for a rapid reopening of the country — at times unnerving health experts, who fear a rushed resumption of normal life will only lead to more death. He recently tweeted in apparent encouragement of people in Minnesota, Michigan and Virginia protesting those states’ coronavirus-related restrictions. But Trump has also publicly disagreed with Georgia’s recent decision to allow certain businesses to reopen.

“Many policies that would be unthinkable in regular times have become commonplace in recent weeks, and we do not want to unduly interfere with the important efforts of state and local officials to protect the public,” Barr wrote in the memo. “But the Constitution is not suspended in times of crisis. We must therefore be vigilant to ensure its protections are preserved, at the same time that the public is protected.”

Barr wrote that Eric Dreiband, the Justice Department’s assistant attorney general for civil rights, and Matthew Schneider, the U.S. attorney for the Eastern District of Michigan, would oversee the effort.

He compared the directive to a similar decree he issued telling prosecutors to prioritize cases of those trying to profit from the pandemic. That memo sparked a significant push among U.S. attorneys to bring coronavirus-related prosecutions.

Barr has previously been outspoken about his wariness of aggressive restrictions to prevent the spread of coronavirus. He told Fox News earlier this month that he considered some of the measures “draconian” and that he would be “keeping a careful eye on” the situation — particularly as April turned to May, and the federal government updated its social distancing guidelines.

“When this period of time, at the end of April, expires, I think we have to allow people to adapt more than we have, and not just tell people to go home and hide under their bed, but allow them to use other ways — social distancing and other means — to protect themselves,” Barr said.

Barr repeated some of those sentiments in a more recent interview with conservative radio host Hugh Hewitt, saying “the idea that you have to stay in your house is disturbingly close to house arrest” and cryptically suggesting the federal government might “have to address” cases in which state governors impinge on civil liberties.

But in both instances, Barr stressed that states have the authority to restrict Americans’ constitutional rights in cases of emergency. And in the more recent interview with Hewitt, he said the federal government was wisely deferring to state leaders.

“That can be a messy business, but at the end of the day, the better approach than trying to dictate everything from Washington,” Barr said.

Barr said the Justice Department has sought to “jawbone” some local officials who have exceeded their authority, but so far it has intervened in only a single lawsuit over coronavirus restrictions, appearing to back a Greenville, Miss., church which had sued over the city’s efforts to shut down drive-in religious services.

Even in that instance, the department did not unequivocally support Temple Baptist Church in its legal statement of interest, though it said the circumstances the church described “suggest that the city singled out churches for distinctive treatment,” which would be unconstitutional.

The department also stressed in its filing that following state and local restrictions was the “best path to swiftly ending COVID-19’s profound disruptions to our national life and resuming the normal economic life of our country.” The city ultimately backed down in the suit.