Former Wyoming Republican Rep. Liz Cheney said Monday the Supreme Court should find former President Donald Trump has “no immunity” from prosecution and that any delay of his federal trial will have a “profoundly negative impact.”

“If delay prevents this Trump case from being tried this year, the public may never hear critical and historical evidence developed before the grand jury, and our system may never hold the man most responsible for Jan. 6 to account,” Cheney, who is one of Trump’s biggest critics on the Right, wrote in a New York Times op-ed.

Cheney’s remarks come just days before the high court is slated to hear arguments on Thursday over whether Trump may enjoy immunity from prosecution against special counsel Jack Smith’s 2020 election subversion case.

Smith has repeatedly stressed there is a significant “public interest” in holding a trial over the four-count indictment before the November presidential election and has likewise urged haste when deciding the immunity dispute.

Trump’s lawyers recently conceded to the high court that if it does not grant him full immunity from Smith’s case, then it should at least send the case back to U.S. District Judge Tanya Chutkan to determine whether any partial theory of immunity would apply to his case, an outcome that would still push the trial many months.

Legal experts said the case could become inundated with more delays if Trump gets the chance to question to what extent each of the four counts in the indictment rests on official acts of the then-president.

Smith argues Trump’s alleged involvement in a scheme to submit fake election certificates to Congress in hopes it would nullify Joe Biden’s victory constituted a series of crimes. Trump argues he was merely expressing his concerns over alleged voter fraud and has pleaded not guilty to the charges.

Cheney, who was once the chairwoman of the Republican Conference, said the pace of the Supreme Court is imperative for the public witness “historic testimony” that is “likely to remain secret until the special counsel presents his case at trial.”

Trump already sustained setbacks over his immunity theory after Chutkan and a three-judge panel on the U.S. Court of Appeals for the District of Columbia Circuit rejected his bid to ward off the charges.

“Early this year, a federal appeals court took less than a month after oral argument to issue its lengthy opinion on immunity,” Cheney said, adding that “history shows that the Supreme Court can act just as quickly, when necessary.”

Trump’s case on Thursday will be the last one argued for this current term, and a decision over the dispute could come between early May and late June.