Chester County on Thursday ordered a hand recount of 190,462 paper ballots cast in last month's election, as former Green Party presidential candidate Jill Stein continues her bid for a statewide recount.

The county's Board of Elections, which consists of the three county commissioners, ruled that the Department of Voter Services must recount the ballots in 143 of the 228 precincts for the presidential and U.S. Senate races.

Many counties have adopted electronic voting systems, but Chester relies almost exclusively on paper ballots. Of nearly 275,000 ballots cast there last month, all but about 850 were on paper.

The ruling there was the latest in Stein's increasingly improbable bid to overturn the results that gave President-elect Donald Trump the state's 20 electoral votes and helped him clinch the White House.

On Thursday, an Allegheny County judge denied a request for a forensic examination of machines there, and officials in Bucks and Montgomery Counties have dismissed petitions for recounts. Philadelphia election officials recounted votes in 75 of 1,686 voting divisions.

The petitions have been filed by voters but organized by Stein's campaign lawyers and supporters.

On Friday, a federal judge in Philadelphia will hear arguments in a lawsuit Stein's lawyers filed requesting a statewide recount of paper ballots and a forensic examination of voting machines. The effort has been aimed at determining whether there were irregularities with electronic voting machines.

State election officials, Trump's campaign, and the state Republican Party filed motions Thursday asking the judge to throw out the lawsuit. They argue that Stein lacks standing because there is no way any potential change in the vote count will end with Stein as the winner.

State officials also said any suggestion that hackers changed the outcome of the race is "rank speculation."

The recount effort in Chester County began Thursday afternoon and will "continue until completion," according to county spokeswoman Rebecca Brain. Tuesday is the federal deadline for the state to certify votes.

Hillary Clinton won Chester County, the only county bordering Philadelphia with a Republican voter-registration edge.

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