WASHINGTON (Reuters) – The U.S. Supreme Court plans to issue at least one ruling on Monday, the day before Colorado holds a presidential primary election in which a lower court kicked Republican frontrunner Donald Trump off the ballot for taking part in an insurrection during the 2021 Capitol attack.

The court, in an unusual Sunday update to its schedule, did not specify what ruling it would issue. But the justices on Feb. 8 heard arguments in Trump’s appeal of the Colorado ruling and are due to issue their own decision.

Colorado is one of 15 U.S. states and an American territory holding primary elections on “Super Tuesday.” Trump is the frontrunner for the Republican nomination to challenge Democratic President Joe Biden in the Nov. 5 U.S. election.

The Republican party of Colorado has asked the Supreme Court, whose 6-3 conservative majority include three justices appointed by Trump, to rule before Tuesday in the ballot eligibility case.

During arguments in the case, Supreme Court justices signaled sympathy toward Trump’s appeal of a Dec. 19 ruling by Colorado’s top court to disqualify him from the state’s ballot under the U.S. Constitution’s 14th Amendment.

In another case with high stakes for the election, the Supreme Court last Wednesday agreed to decide Trump’s claim of immunity from prosecution for trying to overturn his 2020 election loss.

(Reporting by Doina Chiacu; Editing by Scott Malone and Will Dunham)