The U.S. Justice Department on Friday threw its support behind a Philadelphia veterans group suing to overturn the city’s ban on large, permitted events during the pandemic, even as coronavirus cases surge here and across the state.

In a “statement of interest” filed in the case in federal court, U.S. Attorney William M. McSwain accused city officials of unconstitutionally discriminating against certain types of speech by banning large, planned events like the Mummers Parade, while not applying those same standards to spontaneous protests that have sprung up against racial injustice over the past five months.

“This is a case about more speech, not less,” he wrote. “It is also a case about Philadelphia’s double standard whereby it treats some types of speech … more favorably than others. There is no possible public health justification for this double standard.”

The filing was submitted the same day that the Philadelphia Vietnam Veterans Memorial Society filed its lawsuit challenging the ban, naming Mayor Jim Kenney and Managing Director Tumar Alexander as defendants. The society is represented by attorneys from Faegre Drinker, the law firm at which McSwain was a partner before President Donald Trump appointed him the top federal prosecutor in the region in 2017.

U.S. District Judge Nitza Quiñones-Alejandro has not yet scheduled a hearing date for the case.

At a news conference Friday, McSwain said that the veterans group approached him seeking support for their legal challenge after members read news articles on a letter he wrote questioning the event ban in July soon after Kenney announced it.

But Kenney’s office noted it hadn’t been granting permits to protesters, either. The ban on large, planned gatherings applies to everything from permitted block parties to parades that draw thousands. A spokesperson for the mayor accused McSwain of “inciting” the veterans' lawsuit during “one of the most dangerous times in our pandemic.”

This week, Philadelphia has reported a seven-day rolling average of nearly 350 new coronavirus diagnoses a day — a level of infections not seen since the spring. And while the city’s case counts remain slightly below the peak they reached in early May, statewide positive tests have surged to record heights and had surpassed 2,000 on four consecutive days, the state said Friday.

“The only reason that the virus was beaten back at that time was the strict measures the city implemented to limit public congregation and to promote social distancing,” said Mike Dunn, a spokesperson for the mayor. “Efforts to further roll back these common sense, life-saving restrictions will exacerbate the situation, leading to more infections, hospitalizations, and deaths.”

McSwain shot back: “I haven’t heard a word from the mayor that the outdoor protests have caused the spread of COVID-19.”

The U.S. Attorney’s filing Friday echoed similar arguments made in other Justice Department challenges to coronavirus safety restrictions it has deemed unconstitutional across the country. Trump, meanwhile, has repeatedly attacked Gov. Tom Wolf’s statewide rules during the pandemic limiting events. He complained recently that Wolf’s rules have made it harder for him to find venues for his campaign rallies, some of which have been linked to coronavirus outbreaks.

“The solution is not to limit protests," McSwain said Friday. But "rather … to eliminate the event moratorium [altogether] and allow all speakers to express themselves in accordance with their constitutional rights.”

In their suit, the Philadelphia Vietnam Veterans Memorial Society argued that Philadelphia’s events ban — which was originally slated to last through February — is overly lengthy, favors those willing to ignore the city’s permitting process, and does not take into account evolving understandings of COVID-19 transmission, especially in outdoor space.

The virus has been blamed for 1,875 deaths in Philadelphia, and officials advise residents to wear masks and assume that everyone with whom they come in contact is infected.

In announcing that more students would be allowed to return to the campus for the spring semester, the University of Pennsylvania said that mask-wearing and other protocols would be in place.

In addition, those who do return will have to agree to be tested twice a week for the virus, the school said. Some other colleges nationally have required that much testing, though none in the Philadelphia region.

Ursinus College in Montgomery County requires students to be tested once a week.

Staff writers Laura McCrystal, Susan Snyder, and Rob Tornoe contributed to this article.