Zambia’s opposition leader Hakainde Hichilema will go on trial at a high court on treason charges, a magistrate said on Thursday, in a case that has stoked political tensions following a contested election last year.

Hichilema, leader of the United Party for National Development, was arrested in April when police raided his home and charged him with trying to overthrow the government.

An economist and businessman known as “HH”, Hichilema was defeated last August by President Edgar Lungu in an election he said was fraudulent. His attempts to mount a legal challenge have so far been unsuccessful.

“I hereby commit the accused persons forthwith to the high court for trial,” magistrate David Simusamba said before a packed court room. He did not specify which court would hear the case.

Hichilema’s lawyers previously said the case should not proceed to a high court because the officer who issued the trial papers had no authority to do so.

Looking composed in a red coat and red shirt, Hichilema told journalists he hoped the trial would start quickly.

“We have always been ready for trial. I am in court because of hatred. We need a dedicated judge to deal with our matter expeditiously,” Hichilema said, before being led back to prison.

Defence lawyer Jack Mwiimbu told journalists a high court judge would now have to set the dates for the trial.

(Reporting by Chris Mfula; Editing by Joe Brock)