In a move that overturns a key Justice Department policy enacted by the Obama administration, Attorney General Jeff Sessions has directed federal prosecutors around the country always to be as harsh and punitive as the law allows when making charging decisions. In a policy memo issued Thursday, Sessions formally rescinded a pair of directives issued by Eric Holder, the former attorney general, that instructed prosecutors dealing with drug cases to consider whether the most severe punishment available was fair and proportional, and to consider not specifying the quantity of drugs at issue so as to avoid triggering mandatory minimum statutes.

The Holder policy, which tough-on-crime zealots like Sessions believe made it too hard for prosecutors to pressure defendants into guilty pleas, came as a response to the unspeakably rapid expansion of the prison population. Holder said at the time that “too many Americans go to too many prisons for far too long and for no good law enforcement reason,” adding that “although incarceration has a role to play in our justice system, widespread incarceration … is both ineffective and unsustainable,” “imposes a significant economic burden … and comes with human and moral costs are impossible to calculate.”

In his memo Thursday, Sessions asserted that the new policy, which is expected to increase the number of people in the federal prison population, “is moral and just.”

While the policy leaves room for prosecutors to exercise “good judgment” in sparing some defendants the most severe punishment when making indictments, such deviations from the directive will require them to document “unusual facts” and seek formal approval from the Justice Department.