HARRISBURG — Former Green Party presidential candidate Jill Stein wants Pennsylvania to block Philadelphia from using new touchscreen machines the state is buying ahead of the 2020 election and threatened court action Wednesday if it doesn't do so promptly. Stein and a group of plaintiffs could take the state back to Philadelphia's federal court, where they filed an agreement last year to settle their lawsuit over vote-counting in 2016's election. Stein and the other plaintiffs made the request in writing to Pennsylvania's Department of State, which oversees elections.

“We must protect our vote and we must protect the authenticity of our vote,” Stein told supporters during her announcement in front of Philadelphia's federal courthouse Wednesday.

The department has 30 days under the agreement to respond. On Wednesday, it did not say whether it would consider decertifying the machines, although a spokeswoman pointed out that it recertified the system last month after originally certifying it last year.

The lawsuit had accused Pennsylvania of violating the constitutional rights of voters, saying its voting machines in 2016 were susceptible to hacking and barriers to a recount were pervasive. Gov. Tom Wolf's administration settled the lawsuit in part by affirming a commitment it had made to push Pennsylvania's counties to buy new voting systems that leave a verifiable paper trail by 2020.

But Stein said Pennsylvania's certification of the ExpressVote XL touchscreen system made by Omaha, Neb.-based Election Systems & Software violates that agreement, in part because the machine does not meet the agreement's requirements for a voter-verifiable paper ballot.