Cameroon's main opposition leader Maurice Kamto, who was runner-up in last year's presidential election, on Friday goes to trial in a military court on insurrection charges that have sparked an international outcry.
Kamto and dozens of political allies and supporters face charges of insurrection, hostility to the motherland and rebellion, crimes which could carry the death penalty.
His trial will go ahead despite repeated protests from France, the United States, and the European Union, who have been calling for his release from detention for eight months.
"There is no justification for Mr. Kamto and his supporters to have been incarcerated for eight months in these conditions," their French lawyer Antoine Vey told AFP.
"None of them took part in acts of violence, none called for acts of violence or rebellion, there is no reason for their arrest other than a political motive."
Kamto, the head of the opposition Movement for the Rebirth of Cameroon (MRC), was arrested in late January after months of peaceful opposition protests over the results of the October 2018 presidential election.
The MRC charges the election was rigged in favour of President Paul Biya, who has been in power for 36 years. Kamto believes he won the election.
The crackdown on the opposition caused outrage among rights groups and many western governments.
In March, the US assistant secretary of state for African affairs Tibor Nagy, told Radio France Internationale that Cameroon would be "very wise" to release Kamto because his detention is widely perceived as politically motivated.
A top European Union official criticised the arrests and the military court's "disproportionate" proceedings against them.
France, the country's former colonial power, in May also demanded the release of Kamto and his supporters.
Kamto, 65, and his allies said in a letter that they were "ready to face justice so the truth would come out in this case", demanding free public and press access to the courtroom.
Along with the political protests, Biya is also facing a struggle on other fronts.
Since 2017, fighting between troops and English-speaking separatists demanding independence in two western regions has killed hundreds, forced nearly 500,000 people from their homes and filled jails with anglophone activists accused of militancy.
In the north of the country, Boko Haram's nearly 10-year Islamist insurgency which is based in northeast Nigeria has more recently spilled over into Cameroon and other neighbours, Agence France Presse reports