Donald Trump is not immune from prosecution for alleged crimes he committed during his presidency to reverse the 2020 election results, a federal appeals court said Tuesday. The ruling is a major blow to Trump's key defense thus far in the federal election subversion case brought against him by special counsel Jack Smith. The former president had argued that the conduct Smith charged him over was part of his official duties as president and therefore shield him from criminal liability. The ruling from the three-judge panel was unanimous. The three-judge panel who issued the ruling Tuesday includes two judges, J. Michelle Childs and Florence Pan, who were appointed by Joe Biden and one, Karen LeCraft Henderson, who was appointed by George H.W. Bush. In a statement Tuesday, Trump spokesman Steven Cheung said to expect an appeal. "President Trump respectfully disagrees with the DC Circuit's decision and will appeal it in order to safeguard the Presidency and the Constitution," Cheung said. The court is giving Trump until Feb. 12 to file an emergency stay request with the Supreme Court, which would stop the clock while his attorneys craft a more substantive appeal on the merits. If he is successful with that, the criminal trial will not resume until after the high court decides what to do with his request for a pause. If proven, the court wrote, Trump's efforts to usurp the 2020 presidential election would be an "unprecedented assault on the structure of our government." "It would be a striking paradox if the president, who alone is vested with the constitutional duty to 'take Care that the Laws be faithfully executed, were the sole officer capable of defying those laws with impunity," they wrote. The judges flatly rejected Trump's claim that his criminal indictment would have a "chilling effect" on future presidents. Trump' attorneys had argued that if future executives believed that they could be indicted for their "official acts" as president, they would be more hesitant to act within their role. The panel wrote: "The risks of chilling presidential action or permitting meritless, harassing prosecutions are unlikely, unsupported by history and 'too remote and shadowy to shape the course of justice.' "We therefore conclude that functional policy considerations rooted in the structure of our government do not immunize former Presidents from federal criminal prosecution." Trump faces four counts from Smith's election subversion charges, including conspiring to defraud the United States and to obstruct an official proceeding. The former president has pleaded not guilty. The White House and President Joe Biden's re-election campaign declined to comment. Trump has argued that he was working to "ensure election integrity" as part of his official capacity as president, and therefore he is immune from criminal prosecution for trying to overturn the election results. His lawyers have also asserted that because Trump was acquitted by the Senate during impeachment proceedings, he is protected by double jeopardy and cannot be charged by the Justice Department for the same conduct. The district judge overseeing Trump's criminal case in DC rejected Trump's immunity arguments in December, writing that being president does not "confer a lifelong 'get-out-of-jail-free' pass." Trump quickly appealed that decision to the DC Circuit, which agreed to expedite its review of the matter. The appeals court found that Trump is not protected from criminal prosecution under the separation of powers clause. "Here, former President Trump's actions allegedly violated generally applicable criminal laws, meaning those acts were not properly within the scope of his lawful discretion," they wrote, meaning that existing case law "provide him no structural immunity from the charges in the Indictment." The court said that Trump asked them to find "for the first time that a former president is categorically immune from federal criminal prosecution for any act conceivably within the outer perimeter of his executive responsibility," they wrote. — CNN