A Pennsylvania judge on Wednesday sided with Donald Trump’s campaign and agreed to extend an in-person voting option in suburban Philadelphia, where long lines on the final day led to complaints voters were being disenfranchised by an unprepared election office.

A lawsuit demanding an extension of Tuesday’s 5pm deadline in Bucks county was filed on Wednesday morning after long queues outside the county’s election office on the last day for applications led to security guards cutting off the line and telling some of those waiting they would not be able to apply.

Videos of the scenes were widely circulated on social media, fuelling rumours of voter suppression.

The Trump campaign was joined by the Republican National Committee (RNC) and the Republican Senate candidate Dave McCormick in the lawsuit, alleging that voters waiting outside election offices for mail ballots were turned away empty-handed and ordered to leave after the deadline expired at 5pm on Tuesday.

“This is a direct violation of Pennsylvanians’ rights to cast their ballot – and all voters have a right to STAY in line,” the Trump campaign said.

Judge Jeffrey Trauger said in a one-page order that Bucks county voters who want to apply for an early mail ballot now have until Friday.

The queues for late mail ballots were a result of Pennsylvania not having an early on-site voting system at designated spots, as is the case in some other states. Instead, voters can apply for ballots on demand at election offices before filling them out and submitting them on the spot, a procedure that takes about 10 minutes.

The flood of late applicants overwhelmed electoral workers in Bucks county’s administration building in Doylestown, leading to a long queue, which was cut off at about 2.45pm on Tuesday, according to CBS.

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Michael Whatley, the chair of the Republican National Committee, told a rally in Allentown, Pennsylvania on Tuesday that Democratic election officials were trying to suppress Republican votes.

“Democrat election officials are seeing our numbers. They’re seeing our turnout. They are seeing us breaking early vote records across Pennsylvania,” he said. “They are terrified. And they want to stop our momentum. We are not going to let them suppress our votes.”

In a statement, Bucks county admitted there had been some “miscommunication” from officials, resulting in those waiting “briefly being told they could not be accommodated”. But this was subsequently corrected, allowing them to submit applications.

“Contrary to what is being depicted on social media, if you are in line by 5pm for an on-demand mail-in ballot application, you will have the opportunity to submit your application for a mail-in ballot,” the county said.

The legal action raised the prospect of further possible controversy after election day in Pennsylvania – arguably the most important battleground state in next Tuesday’s election – after Trump baselessly accused election officials of cheating.

“Pennsylvania is cheating, and getting caught, at large scale levels rarely seen before,” Trump posted on his Truth Social platform, without providing evidence. “REPORT CHEATING TO AUTHORITIES. Law Enforcement must act, NOW!”

The allegation was dismissed by Pennsylvania’s Democratic governor, Josh Shapiro, who accused the former president of seeking to undermine public trust in the integrity of election officials.

“In 2020, Donald Trump attacked our elections over and over,” posted Shapiro, who was Pennsylvania’s attorney general four years ago when Trump tried to overturn Joe Biden’s victory. “He’s now trying to use the same playbook to stoke chaos … we will again have a free and fair, safe and secure election – and the will of the people will be respected.”

Most polls show Kamala Harris with a tiny lead over Trump in Pennsylvania, which has more electoral college votes than any other battleground state and which both candidates have campaigned in more than any other state.