HARRISBURG — Pennsylvania is facing another lawsuit over its certification of a voting machine bought by Philadelphia and that was at the center of an undercount in one Pennsylvania county’s election last month.

The lawsuit was filed late last week by a pair of election security advocacy organizations and 13 registered voters who live in Philadelphia or Northampton County, where the undercount occurred.

The lawsuit asks the state Commonwealth Court to block Pennsylvania’s certification of the ExpressVote XL touchscreen system.