A Georgia appeals court has agreed to review a lower court ruling that kept District Attorney Fani Willis on Donald Trump's election subversion case.
The former president has tried to have Ms Willis removed from the case, arguing her romantic relationship with another prosecutor created a conflict.
Superior Court Judge Scot McAfee last month found no conflict of interest but allowed for his ruling to be appealed.
This latest development is expected to delay the start of trial.
No date had yet been set for it to begin, but the appeal makes it increasingly likely that the trial will take place after November's presidential elections. Mr Trump is the presumptive Republican standard-bearer.
Mr Trump and 18 others are being prosecuted in Georgia for conspiracy to overturn the state's 2020 election results, which they deny.
The case was nearly upended after one of the co-defendants, Michael Roman, claimed that Ms Willis - the Fulton County District Attorney overseeing the case - was improperly benefitting from a romantic relationship with lead prosecutor Nathan Wade.
Several of Mr Roman's co-defendants, including Mr Trump, joined the motion to have Ms Willis disqualified and the charges dismissed.
Over several tense days in court in February, Ms Willis admitted she had had relationship with Mr Wade but denied that she had benefitted financially.
Judge McAfee ultimately found in March that Ms Willis had a "serious lapse in judgment" and that the relationship damaged the case with the "appearance of impropriety". But he ruled the case could continue with Ms Willis as long as Mr Wade resigned. He stepped down soon after.
Prosecutors had asked the Georgia court of appeals not to hear arguments on Mr McAfee's ruling, but their request was unsuccessful.
Mr Trump now has 10 days to file a notice of appeal. Once the appeal court makes its decision, either side could appeal again and bring the case to the Georgia Supreme Court.
In a statement to US media, Mr Trump's lead attorney in Georgia said the former president "looks forward to presenting interlocutory arguments to the Georgia Court of Appeals as to why the case should be dismissed and Fulton County DA Willis should be disqualified for her misconduct in this unjustified, unwarranted political persecution".
The Fulton County district attorney's office did not respond to a request for comment.
The Georgia election interference case is one of four criminal cases Mr Trump faces.
Three are unlikely to take place before the November elections. The fourth - a criminal hush-money trial - is currently underway in New York.
On Tuesday, a judge in Florida indefinitely postponed Mr Trump's classified documents case there, cancelling the planned 20 May start date.
