The treason trial of Tanzanian opposition leader Tundu Lissu resumed on Monday after nearly six months of suspension, reviving a case that has drawn sustained international scrutiny over the state of democracy in East Africa's largest country. Lissu, chairman of Chadema — Tanzania's main opposition party — has been held in custody since April 2025, charged with treason, an offence that carries the death penalty under Tanzanian law.

The case centres on allegations that Lissu, who was Chadema's presidential candidate in the 2025 elections, called for those elections to be blocked unless electoral reforms were first adopted. At Monday's hearing before a three-judge bench at the High Court in Dar es Salaam, Tanzania's commercial capital, Lissu appeared smiling and with his fist raised as he entered the courtroom, telling reporters he welcomed the chance to publicly challenge what he described as government misconduct. Speaking outside the courthouse, he accused prosecutors of deliberately stalling proceedings to extend his pre-trial detention, saying they sought "to waste time so that I can continue to remain in remand custody."

The trial had been suspended since February after prosecutors attempted to introduce additional evidence — a request that Tanzania's Court of Appeal rejected last month as having no legal foundation. That ruling is significant: with the additional evidence disallowed, Chadema's defence team intends to ask the High Court to find that the prosecution has failed to establish a sufficient case, and to dismiss the charges entirely. The party's spokesperson, Brenda Rupia, raised further doubts about the integrity of the proceedings, alleging that a key prosecution witness may have assumed the identity of a man who died in 2021, forcing a pause in hearings to verify who the individual actually is. "The government dares to bring forward people supposedly from the police, while they are actually someone else entirely," she said. The trial is scheduled to continue until 7 September.

Chadema has framed the prosecution as a politically motivated attempt to silence legitimate opposition, describing the hearing as a critical test of Tanzania's commitment to the rule of law. Lissu's supporters accuse President Samia Suluhu Hassan of reviving the repressive political practices associated with her predecessor, the late President John Magufuli, whose tenure was widely criticised by rights groups. The government has consistently denied those accusations. Rupia also questioned the structural basis of the treason charge itself, noting that treason by definition requires a conspiracy yet only one person stands accused — and she expressed deep scepticism about judicial independence, saying Tanzanians have lost faith in the country's court system more broadly. The case will be closely watched as a barometer of democratic space in Tanzania ahead of any further political activity.