President Donald Trump's campaign sought on Wednesday to reintroduce claims to a Pennsylvania election lawsuit that it removed three days ago, saying it would ask that Trump be declared the winner of the battleground state.

In a court filing, the campaign sought permission from U.S. District Judge Matthew Brann to put back legal claims that it dropped on Sunday from its Nov. 9 lawsuit. They said Republican observers were denied access to the counting of mail-in ballots, an assertion election officials dispute.

In the court filing, the campaign said the narrowing of the case had been "inadvertent" and due to miscommunication. The campaign said on Monday it had "strategically decided to restructure its lawsuit" when it removed the claims.

The lawsuit also alleges inconsistent treatment by county election officials of mail-in ballots. Some counties notified voters that they could fix minor defects such as missing dates while others did not.

The campaign lawsuit seeks to prevent the state from certifying the election result, citing the disparate policies. Brann expressed skepticism of that request at a hearing on Tuesday.

The lawsuit is deeply flawed and does not give Trump "any viable path to overturning the results," said Justin Levitt, a Loyola Law School professor who has been tracking the litigation.

The amended filing "does not offer any indication that a number of ballots sufficient to make up the difference in the election were invalid," Levitt said, adding that "courts won't toss ballots out (or otherwise stop an election tally in progress) without actual proof that the ballots in question were invalid."

Republican Trump's campaign has filed a flurry of lawsuits in a long-shot bid to reverse the election, which Democratic candidate Joe Biden won with 306 electoral votes to Trump's 232. The winner needs 270, and Trump would have to flip the outcome in Pennsylvania, with 20 electoral votes, and two other states.

The president has claimed without evidence that the election was stolen.

A Reuters poll on Wednesday showed about half of Republicans believe Trump had the election stolen from him. 

Earlier on Wednesday, the Pennsylvania Supreme Court said it would take up an appeal in a separate lawsuit by the Trump campaign challenging thousands of mail-in votes in Philadelphia that were missing information on the return envelopes.

Biden won Pennsylvania by around 82,000 votes, according to Edison Research.

(Reporting by Tom Hals and Jan Wolfe, Noeleen Walder; editing by Cynthia Osterman and Grant McCool) ((thomas.hals@thomsonreuters.com; +1 610 544 2712; Reuters Messaging: thomas.hals.thomsonreuters.com@reuters.net))