U.S. Attorney William McSwain made the request, despite the fact that Judge Gerald McHugh has already ruled that the facility is not illegal.
McSwain reasserted arguments he made last year in trying to halt the push for a safe injection site, arguments the judge rejected in a 56-page opinion in October.
A few days later, McSwain vowed that he would prosecute anyone who opened such a site regardless of the judge's opinion.
Earlier this month, the nonprofit Safehouse asked McHugh for a declaratory judgment in the case so it can proceed with plans to open a facility without fearing prosecution.
A Safehouse official says the board is studying the U.S. attorney's latest request — filed Friday evening — but believes the judge has already addressed all the arguments McSwain raises and hopes he will declare Safehouse a legal pursuit.
Philadelphia had more than 1,100 overdose deaths in 2018.
2019 numbers are still being collected.