WASHINGTON (AP) — A federal judge in Virginia has delayed the trial of President Donald Trump’s campaign chairman, Paul Manafort.

U.S. District Judge T.S. Ellis III says in an order Friday that he’s pushing back Manafort’s trial on tax evasion and bank fraud charges because of a medical procedure involving a member of Ellis’ family. Manafort’s trial is now scheduled to begin July 24.

The judge is considering Manafort’s challenge of special counsel Robert Mueller’s authority.

Manafort argues that Mueller shouldn’t have been able to prosecute him because the charges don’t stem directly from Russian election interference. Prosecutors have countered that Mueller was specifically authorized to investigate Manafort for financial crimes and his political work in Ukraine.

A judge in Washington has rejected Manafort’s argument in his separate criminal case there.