Pennsylvania’s absentee ballot deadline must be extended during the coronavirus emergency or some voters will be unconstitutionally disenfranchised, a group of nonpartisan advocacy groups said in a lawsuit filed Monday.

State law requires mail ballots to be received at county offices by an election day. Instead, those ballots should be counted if they are postmarked by that day and received within the next week, the suit says.

Different voters, through no fault of their own, would have different access to mail-in voting under the current deadlines, the lawsuit says, based on their particular counties’ processing of ballots and the speed of mail service. And the only alternative — voting in person — may be disproportionately risky for some.

That, the plaintiffs argue, would violate the state constitution’s guarantee that “elections shall be free and equal.”

“Elections are not ‘free’ when voters must risk their health and lives to ensure their votes will be counted,” the lawsuit says. “And elections are not ‘equal’ when similarly situated citizens who timely request absentee and mail-in ballots may or may not have their votes counted based on factors outside their control.”

The plaintiffs are represented by the Philadelphia-based Public Interest Law Center and Washington-based Arnold & Porter Kaye Scholer LLP, bringing back together much of the team that in 2018 successfully challenged Pennsylvania’s congressional map as an unconstitutional partisan gerrymander.

The suit also argues that the deadlines will violate the state constitution’s protection of free speech, equal protection for all people, and other provisions.

Under normal conditions, the lawsuit says, the plaintiffs have no quarrel with the absentee ballot deadlines in the law. But during a public health crisis in which voting in person can risk voters’ lives, the suit says, the law is unconstitutional.

Consider that some counties are already falling behind in processing mail ballot requests, and that mail delivery can be unpredictable, said Mimi McKenzie, legal director of the Public Interest Law Center. That means some voters will likely receive their ballots too late to return, or will return them too late to be counted.

Voters who receive their ballots close to the election day will instead have to go to a polling place if they want to be sure their vote actually counts.

“It’s putting people in that circumstance of having to choose between having their vote count, which is of course a fundamental right of all American citizens,” McKenzie said, “and having to risk their life or the lives of their families and neighbors.”

And some voters, the plaintiffs argue, could be at greater risk than others.

“Because the risks of voting in person during a pandemic vary across the population — along axes like age, race, and disability status — the ability of two similarly situated individuals who have requested mail-in ballots to vote in person if necessary will differ significantly,” the suit says, arguing that “a younger, healthier voter will be more realistically able to remedy the situation by voting in person.”

The lawsuit was filed in the Pennsylvania Supreme Court, which has direct jurisdiction over challenges to the revised voting law that established the absentee ballot deadlines. Its plaintiffs are Suzanne Erb, the chair of the Disability Rights Pennsylvania board; Disability Rights Pennsylvania; the Barristers’ Association of Philadelphia; SeniorLAW Center; and Southeast Asian Mutual Assistance Associations Coalition.

The defendants are officials at the Pennsylvania Department of State, which declined to comment Monday because it does not comment on active litigation.