Sen. Rand Paul (R-Ky.) strongly opposes the new charging policy announced by U.S. Attorney General Jeff Sessions and has co-sponsored a sentencing reform bill. (J. Scott Applewhite/AP)

Attorney General Jeff Sessions’s former colleagues in the Senate are pushing back on his order to federal prosecutors to pursue the most severe penalties possible for defendants, including mandatory minimum sentences, and introducing legislation to give federal judges more discretion to impose lower sentences.

Sen. Rand Paul (R-Ky.), who co-sponsored the legislation, said that Sessions’s new policy will “accentuate” the existing “injustice” in the criminal justice system.

“Mandatory minimum sentences disproportionately affect minorities and low-income communities, while doing little to keep us safe and turning mistakes into tragedies,” Paul said. “As this legislation demonstrates, Congress can come together in a bipartisan fashion to change these laws.”

Last week, in a two-page ­memorandum to federal prosecutors across the country, Sessions overturned former attorney general Eric H. Holder Jr.’s sweeping criminal charging policy that instructed his prosecutors to avoid charging certain defendants with offenses that would trigger long mandatory minimum sentences. In its place, Sessions told his more than 5,000 assistant U.S. attorneys to charge defendants with the most serious crimes, carrying the toughest penalties.

After Sessions released his new policy, it drew bipartisan criticism that the policy would mark a return to mass incarceration, especially of minorities. It was embraced, however, by the National Association of Assistant United States Attorneys, whose president said it would restore more tools to do their jobs.

“An outgrowth of the failed war on drugs, mandatory sentencing strips critical public-safety resources away from law-enforcement strategies that actually make our communities safer,” said Sen. Patrick J. Leahy (D-Vt.).

Leahy and Paul introduced the Justice Safety Valve Act with Sen. Jeff Merkley (D-Ore.). Rep. Thomas Massie (R-Ky.) and Rep. Robert C. “Bobby” Scott (D-Va.) are introducing a companion bill in the House. The proposed legislation would allow federal judges to tailor sentences on a case-by-case basis. It would also reduce correctional spending, which accounts for nearly one-third of the Justice Department’s budget.

“Attorney General Sessions’s directive to all federal prosecutors to charge the most serious offenses, including [those that trigger] mandatory minimums, ignores the fact that mandatory minimum sentences have been studied extensively and have been found to distort rational sentencing systems, discriminate against minorities, waste money and often require a judge to impose sentences that violate common sense,” Scott said.

During President Barack Obama’s second term, similar sentencing reform legislation was introduced by a bipartisan group of lawmakers.

The legislation, which had 37 sponsors in the Senate, including Sen. Charles E. Grassley (R-Iowa) and Mike Lee (R-Utah), and 79 members of the House, would have reduced some of the long mandatory minimum sentences for gun and drug crimes. It also would have given judges more flexibility in drug sentencing and made retroactive the law that reduced the large disparity between sentencing for crack cocaine and powder cocaine.

The bill, introduced in 2015, had support from outside groups as diverse as the conservative Koch brothers, the NAACP and House Speaker Paul D. Ryan (R-Wis.). But Sessions, then the longtime Republican senator from Alabama, became a leading opponent of the bill and successfully worked with other senators to derail it.

As he has done as attorney general, Sessions said then it was the wrong time to cut prison sentences for drug traffickers and other criminals and cited the spike in crime in several cities and his belief that an era of near-historically low crime rates might be coming to an end.

In a conference call with reporters, Paul acknowledged that lawmakers will have an “uphill battle” getting support from the White House for the sentencing reform bill.