A Tunisian court sentenced presidential candidate Ayachi Zammel to 12 years in prison on Tuesday, amid growing opposition anger against President Kais Saied, whose critics accuse him of using the judiciary to sideline his opponents.

It was the third prison sentence imposed on Zammel in two weeks, just five days before the presidential election in which he is one of just two candidates permitted to stand against Saied. Three other high profile opposition figures were barred.

Abdessattar Massoudi, Zammel's lawyer, said that Zammel was sentenced to 12 years in prison by Tunis court on charges of document falsification. Massoudi described the verdict as "unfair and a farce".

Zammel, head of the opposition Azimoun party, has been jailed since last month on charges of falsifying voter signatures on his candidacy paperwork, accusations he described as manufactured by Saied's government. He has been allowed to continue to stand in the election while jailed.

Political tensions in the North African country have risen ahead of the Oct. 6 election since an electoral commission named by Saied disqualified three other prominent candidates last month, amid protests by opposition and civil society groups.

Tunisia was the only Arab country to emerge with a peaceful democracy from the 2011 "Arab Spring" protests against autocratic rulers across the Middle East and North Africa.

But since being elected in 2019, Saied has gradually amassed greater powers, arguing that he needs them to combat a corrupt elite. He dissolved the elected parliament and began ruling by decree in 2021, a move the opposition described as a coup.

The electoral commission has rejected a ruling by Tunisia's administrative court to reinstate the barred candidates for the upcoming election. Lawmakers loyal to Saied then approved a law stripping the administrative court of authority over election disputes.

The opposition and civil society groups called for a mass protest on Friday against what they describe as Saied’s authoritarian rule, and said they would continue escalation and demonstrations.