Washington DC - The US Supreme Court agreed Monday to decide whether mail-in ballots that arrive after Election Day should be counted, a case that could have repercussions for the 2026 midterm vote.

The case involves a challenge by the Republican National Committee to a law in the southern state of Mississippi that allows ballots to be counted if they arrive within five business days after Election Day.

The ballots must be postmarked by Election Day.

Around 30 US states have similar laws.

Republican President Donald Trump has been a vocal critic of mail-in ballots and has falsely claimed that they contributed to his 2020 election loss to Democrat Joe Biden.

A federal judge ruled in favor of Mississippi, but was overturned by an appeals court panel last year, which said ballots must arrive by Election Day to be counted.

The mail-in ballot case is one of a number of voting rights cases being heard by the conservative-dominated Supreme Court this term.

The court, which includes three justices nominated by Trump, heard arguments last month over the use of race to draw electoral districts.

The Supreme Court is likely to deliver its rulings in the cases by the end of June, which would provide enough time for them to be applied to the November midterm elections.