A Ugandan military court has ruled that prominent opposition figure Kizza Besigye can be tried on the charge of treachery, for which he could face the death penalty if convicted.

The ruling on Tuesday escalates the legal trouble Besigye faces in the run-up to presidential elections scheduled for 2026.

Besigye, who has contested the presidency four times, went missing in the Kenyan capital, Nairobi, on November 16.

Days later, he and his co-accused, an assistant named Obeid Lutale, appeared before a military court in Kampala, the Ugandan capital.

Besigye was charged with illegal possession of a firearm and a charge relating to the alleged solicitation of military support overseas in order to destabilise national security.

The opposition leader, who denied the charges, has since been remanded in custody.

A military prosecutor amended the charge sheet to include treachery and introduced a third suspect, who is a serving army officer.

Besigye, 68, has faced arrest and assault many times in his political career. But he has never been convicted of a crime.

United Kingdom-based Amnesty International has called for Besigye’s release, saying his “abduction clearly violated international human rights law and the process of extradition with its requisite fair trial protections”.

United States-based Human Rights Watch said Besigye’s trial is “the latest example of Uganda’s authorities misusing military courts and military-related charges to clamp down on the opposition”.

President Yoweri Museveni has long been criticised by human rights groups for alleged violations against opposition figures.

Although Museveni, who has held power since 1986, is expected to seek re-election, he has not confirmed it yet.

Museveni has no obvious successor within the ranks of the governing National Resistance Movement, which is creating widespread fears over an unpredictable political transition.

Besigye, a qualified physician who retired from Uganda’s military at the rank of colonel, is a former president of the opposition Forum for Democratic Change (FDC) party.

With Besigye at its helm, the FDC was for many years Uganda’s most prominent opposition group.