(CN) — President Donald Trump’s re-election campaign and the Republican Party have until Friday to provide evidence of mail-in voting fraud in Pennsylvania, a federal judge ordered on Thursday.

Judge J. Nicholas Ranjan, a Trump appointee, decided that it is time for Republicans to back up their unsubstantiated claims of potential massive mail-in voter fraud in the battleground state.

Furthering the president’s fight against mail-in voting as the November election draws near, the Trump campaign and the RNC had sued all 67 counties in Pennsylvania over the state’s absentee ballot drop-off sites in June.

The Republicans asked the court to block officials from counting absentee ballots unless they are mailed by voters to their county election office or dropped off in person rather than at the drop-off sites.

Pennsylvania lawmakers last year passed an extension of mail-in ballot options to allow all residents to vote by mail even if they do not have a stated reason to do so. The Covid-19 pandemic has caused a surge in demand for absentee ballots in the state, which was mitigated during the June 2 primary with the use of absentee ballot drop boxes in some counties.

“Contrary to the direction of Pennsylvania’s General Assembly, defendants have sacrificed the sanctity of in-person voting at the altar of unmonitored mail-in voting and have exponentially enhanced the threat that fraudulent or otherwise ineligible ballots will be cast and counted in the upcoming general election,” the lawsuit states.

But Americans have been voting by mail since the Civil War, and state Democrats wrote the court on Wednesday to condemn the lawsuit as an attempt to spark fear over unproven and unfounded claims of massive mail-in ballot fraud.

The Democratic Party, joined by the Sierra Club, intervened in the case, to ask for evidence that might support the campaign’s allegations.

Judge Ranjan sided with the Democrats on Thursday, giving the Trump campaign one day to respond to Democrats’ requests for evidence of potential mail-in voting fraud with documents, answers and information.

The judge offered one alternative.

“Plaintiffs shall produce such evidence in their possession, and if they have none, state as much,” Ranjan wrote.

So far, the campaign has neither displayed the requested evidence nor offered the testimony of experts, according to the order.

The two-page order came the same day that Trump, during an interview with Fox Business Network, said he opposes a Democrat-led effort to boost funding for the U.S. Postal Service. He appeared to suggest that he is against the proposed postal funding because he wants to prevent an extension of mail-in voting.

A few hours later, while continuing to make false claims about mail-in voting during a press briefing, Trump clarified that he would not veto a coronavirus relief bill just because it includes funding for the U.S. Postal Service.

Andrew Bates, spokesperson for Joe Biden’s campaign, said in a statement that the president is “sabotaging a basic service that hundreds of millions of people rely upon” because he “wants to deprive Americans of their fundamental right to vote.”