(Reuters) - Jones Day will keep representing Republicans in a lawsuit fighting Pennsylvania's deadline extension for mail-in ballots, the firm said Tuesday, after it faced a torrent of online criticism for its work for the Trump campaign.

In the same statement, however, the firm stressed that it is not representing the president or his campaign in "any litigation alleging voter fraud" or litigation looking to overturn the U.S. election.

The wave of criticism against Jones Day, a 2,500-lawyer firm that serves as outside counsel to the Trump campaign, followed a New York Times report Monday on "growing discomfort" among its attorneys over the election challenges. The article cited six Jones Day attorneys who said they believed the goal of the Pennsylvania lawsuit was to erode public confidence in the results of the 2020 U.S. presidential election.

Major U.S. news networks called Democrat Joe Biden as the winner on Saturday. But President Donald Trump has yet to concede, claiming without evidence that fraud was marring the results. His campaign has filed lawsuits in battleground states seeking to overturn the results of the election.

Jones Day distanced itself from that litigation on Tuesday, saying in its statement that it is not "representing any entity in any litigation challenging or contesting the results of the 2020 general election."

Its representation of Pennsylvania Republicans in the case over that state's deadline for mail-in ballots goes back months, the firm said, and it "will not withdraw." It said the case "presents an important and recurring rule-of-law question under the U.S. Constitution." The Supreme Court is currently considering whether to hear the case.

The firm disabled comments on its social media accounts on Tuesday, after the Lincoln Project, a group of Republicans opposed to Trump's re-election with 2.7 million Twitter followers, called on Jones Day attorneys to resign in protest.

Porter Wright Morris & Arthur, another, smaller firm that has represented the Trump campaign on election related litigation, including post-election cases, also faced online blowback Tuesday. It did not immediately respond to request for comment.