The Georgia Court of Appeals on Wednesday stayed the criminal election interference case against former President Donald J. Trump until an appellate panel could resolve the matter of whether the district attorney in Fulton County should be disqualified from prosecuting the case based on a conflict of interest.

In a one-page order, the court stated that any movement at the trial-court level pertaining to Mr. Trump and eight other defendants who have appealed a ruling allowing the prosecutor, Fani T. Willis, to remain on the case was “stayed pending the outcome of these appeals.”

Earlier this week, the appellate court set a tentative date for oral argument of Oct. 4. Legal experts expect the appeals will take months to resolve.

The order was more bad news for critics and opponents of Mr. Trump who had hoped that he would stand trial in Georgia before he faced off against President Joseph R. Biden in the general election. Mr. Trump and a number of his allies were indicted in Georgia last summer in a sweeping racketeering case that accused them of trying to overturn his 2020 election loss in the state.

But the case was derailed earlier this year with the revelation that Ms. Willis had been romantically involved with a lawyer she hired to manage the case.

Defense lawyers argued that Ms. Willis and her entire office should be disqualified, but the presiding judge, Scott McAfee of Fulton County Superior Court, allowed her to stay on it. The defense successfully convinced the state appellate court to hear a pretrial appeal of Judge McAfee’s ruling.

In addition to Mr. Trump, those appealing the disqualification ruling include Rudolph W. Giuliani, Mr. Trump’s former personal lawyer, and Mark Meadows, who was Mr. Trump’s White House chief of staff at the time of the 2020 election.

Last week, Mr. Trump was found guilty of 34 felony counts in a New York court for falsifying records to cover up a sex scandal. He is set to be sentenced in that case on July 11. No trial date has been set in Georgia. Nor have trial dates been set in the two federal criminal cases against Mr. Trump, in Florida and Washington, D.C. Both of those cases have also been slowed down by intense legal skirmishing.

Anthony Michael Kreis, a law professor at Georgia State University, noted that the Georgia Constitution requires the appeals court to rule by March 14. If it does not, he said, the trial court’s ruling would be left in place.

Even after the appeals court decided to hear the disqualification question, Judge McAfee had been moving ahead with other aspects of the case, holding hearings on a number of other pretrial motions filed by defendants. But now, much of that work will be frozen.

Perhaps most significantly, Wednesday’s stay means that Judge McAfee will not be able to rule for now on a motion filed by Mr. Trump that argues that he should have presidential immunity from prosecution in Georgia. Mr. Trump’s lawyers have made a similar argument in his Washington, D.C., case, in which he was charged with conspiring to subvert democracy and stay in power following his 2020 election loss.

The U.S. Supreme Court is expected to issue a ruling on the immunity question in the next few weeks. But now, Mr. Kreis said, Judge McAfee will not be able to make a ruling on the immunity issue in Georgia for months.

“If his ruling on that motion triggers a new round of appeals,” Mr. Kreis said in a text message, referring to Judge McAfee, “Trump may wind up with a procedural reprieve that buys him time until a 2026 trial at this rate.”

The news of the stay revived criticism that Ms. Willis, a Democrat currently seeking a second term as district attorney, had mismanaged the most important case of her career, and one of the most significant state criminal prosecutions in American history.

“She has just stabbed the case right in the heart,” said Clark D. Cunningham, an expert in legal ethics and a law professor at Georgia State University.

Still, the Supreme Court’s decision in February to hear the immunity issue — and the fact that the justices have not yet issued a ruling — also made the possibility of a Georgia trial before the election unlikely. And other pretrial defense motions could have ended up causing similar delays..

A spokesman for the district attorney’s office declined to comment on Wednesday.

In addition to Mr. Trump, Mr. Giuliani and Mr. Meadows, those appealing include Michael A. Roman, a former Trump campaign official; David J. Shafer, the former head of the Georgia Republican Party; Robert Cheeley, a former Trump campaign lawyer; Cathy Latham, a 2020 Trump elector from Georgia; Jeffrey Clark, a former Department of Justice lawyer; and Harrison Floyd, the former head of a group called Black Voices for Trump.