How long will Trump’s appeal to the Supreme Court take – and how likely is he to win?

Votes are still being counted in key swing states such as Pennsylvania and Wisconsin

Donald Trump has vowed to take the 2020 US presidential election to the Supreme Court even as votes are still being counted and the overall result remains unclear.

Mr Trump appears to be in a close battle with Democratic candidate Joe Biden, with the final results in a number of key swing states, such as Pennsylvania and Wisconsin, likely to be decided by mail-in ballots which have not yet been fully counted.

“We’ll be going to the US Supreme Court - we want all voting to stop,” the president said early on Wednesday.

However, it is unclear what exactly Mr Trump will be able to challenge as vote counts routinely continue beyond election day and states largely set their rules for when the count has to end.

Election officials have said they will not count absentee votes which are postmarked for after election day but counting is still taking place in a number of battleground states.

In response to the threat of a Supreme Court challenge, Mr Biden’s campaign said the president’s statement was “outrageous, unprecedented and incorrect”.

If Mr Trump does challenge the result in the Supreme Court, it could take weeks for a decision to be made.

The last time a presidential election went to the US’ top court was in 2000, when a recount dispute in Florida’s vote between George W Bush and Al Gore was settled on 12 December that year.

Following Mr Trump’s threat to challenge the election result this year, the Biden campaign said they were prepared to fight any attempt to prevent votes from being fully counted.

“If the president makes good on his threat to go to court to try to prevent the proper tabulation of votes, we have legal teams standing by ready to deploy to resist that effort,” Jen O’Malley Dillon, Mr Biden’s campaign manager, said in a statement.

Legal experts have also cast doubt on whether Mr Trump could successfully prevent votes from being counted after election day, as the practice is a standard feature of presidential elections.

“I do not see a way that he could go directly to the Supreme Court to stop the counting of votes,” Rick Hasen, a professor of law and political science at the University of California-Irvine, said.

“There could be fights in specific states, and some of those could end up at the Supreme Court. But this is not the way things work.”

Edward Foley, an Ohio State University election law professor, said on Wednesday that he believed valid votes would be counted.

“SCOTUS would be involved only if there were votes of questionable validity that would make a difference, which might not be the case,” Mr Foley said.

“The rule of law will determine the official winner of the popular vote in each state. Let the rule of law work.”

Whatever happens, the Trump campaign would not be able to go directly to the Supreme Court with a claim of fraud - instead, it would have to allege problems with the counting in individual states and start their legal fight in a state or lower federal court.

The top court has already ruled on two significant cases related to the 2020 election, allowing ballots received up to three days after election day to be counted in Pennsylvania but blocking ballots received after election day from being counted in Wisconsin.

As Mr Biden and Mr Trump were separated by less than two percentage points in a number of swing states on Wednesday morning, any decision on contested votes could have a major impact on the overall result of the election.

Additional reporting by AP