Donald Trump’s reelection campaign has filed another federal lawsuit in Pennsylvania, this time seeking an injunction to prevent officials from certifying Joe Biden’s win in the state. Biden was projected as the winner of both Pennsylvania and the presidential race as a whole over the weekend, but Trump has refused to concede.

The new suit alleges that Pennsylvania created and implemented “an illegal ‘two-tiered’ voting system” which “resulted in voters being held to different standards depending on how they chose to exercise their right to vote.” A statement from Trump’s campaign claims the two voting methods — absentee ballots and voting in-person — had different transparency standards and that in-person voters were subjected to more verification requirements.

Meanwhile, mail-in votes, the statement alleges, “lacked all of the hallmarks of transparency and verifiability that were present for in-person voters.”

The statement again refers to Republicans’ claim that they were denied “sufficient monitoring” over the review and counting process for mail-in ballots.

“Voters in Pennsylvania were held to different standards simply based on how they chose to cast their ballot, and we believe this two-tiered election system resulted in potentially fraudulent votes being counted without proper verification or oversight, as well as many voters being disenfranchised simply for casting their votes in-person,” Matt Morgan of Trump’s reelection campaign counsel said. “We will not stop fighting for transparency and integrity in our electoral process and ensuring all Americans can trust in the results of a free and fair election.”

Pennsylvania Attorney General Josh Shapiro responded to the suit on Twitter, writing, “The Trump campaign’s latest filing is another attempt to throw out legal votes — my team and I were already prepared for this.”

“We will protect the laws of our Commonwealth and the will of the people,” he added.

Since Election Day, Trump’s campaign has sued multiple states over claims of fraudulent voting. However, judges have already dismissed cases in Georgia and Michigan.