The legal filing from the Republican presidential candidate and eight co-defendants asks the appeals court to reverse a judge's ruling this month that allowed Fani Willis, the District Attorney of Fulton County, to continue prosecuting the case.

The appeal presents another opportunity for the former U.S. president to delay or derail one of the four criminal cases he faces.

Fulton County Judge Scott McAfee was sharply critical in his ruling of the relationship between Willis and Nathan Wade, an outside lawyer contracted to help lead the prosecution. But he rejected claims from the defense that the romance posed a conflict of interest that would require Willis' office to be removed from the case.

Wade stepped aside from the case after the judge said he would need to withdraw for Willis and her office to continue.

The appeals court has 45 days to decide whether to take up the issue. McAfee gave Trump and the other defendants permission to immediately appeal his ruling, but said he would continue moving the case toward trial during the appeal.

If the court accepts the case, Trump could seek to pause the proceedings while the appeal plays out. A trial date has not yet been set.

McAfee's ruling came after a tumultuous period for Willis, who was grilled by defense lawyers in dramatic testimony about whether she improperly benefited from the relationship through vacations booked by Wade while he was being paid by her office.

Trump's lawyers also accused Willis of "stoking racial animus" in her response to the allegations and misleading the court on when the romantic relationship began.

Willis denied receiving any improper benefit from the relationship, arguing that expenses were divided roughly evenly between her and Wade, and said the romance had no impact on the criminal case.

Willis has cast the disqualification bid as an effort to distract from racketeering and other charges against Trump and 14 co-defendants who are accused of scheming to overturn Trump's narrow defeat in Georgia in the 2020 election. Four others who had been co-defendants in the case have pleaded guilty in deals with the prosecutors.

(Reporting by Andrew Goudsward; Editing by Scott Malone and Bill Bekrot)

By Andrew Goudsward