Turkey's supreme court of appeals on Thursday upheld a prison sentence for the head of the Istanbul branch of the country's main opposition party, a party official told AFP, in a move seen as another crackdown on opponents ahead of next year's presidential election.
In 2019, Canan Kaftancioglu, 50, of the secular Republican People's Party (CHP), was sentenced to nearly 10 years in jail on a range of charges including "terrorist propaganda" and insulting President Recep Tayyip Erdogan.
The charges related mostly to tweets Kaftancioglu posted between 2012 and 2017. She had been free pending the appeals.
The top court on Thursday approved her conviction on three counts with a prison term of four years, 11 months and 20 days.
It was not immediately clear if the ruling means Kaftancioglu will be jailed right away.
The CHP is the second largest party in the Turkish parliament, holding 135 seats.
CHP leader Kemal Kilicdaroglu called on his lawmakers to head to the party's Istanbul headquarters.
"All lawmakers of our party, immediately set off for our Istanbul provincial headquarters," he tweeted right after the ruling.
Kaftancioglu, a doctor by profession, played a key role in the shock victory of the CHP's Istanbul mayor Ekrem Imamoglu in 2019 -- the first time Erdogan's party had lost power in Turkey's biggest city for 25 years.
Kaftancioglu "is my comrade with whom we are striding together to change Istanbul," Imamoglu tweeted.
"I find this decision political and condemn it. I stand by our chairwoman."
Rights groups regularly accuse Erdogan of using the judiciary as a political tool, particularly after thousands of judges were purged in the wake of an attempted coup in 2016.
Erdogan railed against Kaftancioglu after she was appointed to the Istanbul chair in 2016.
"Erdogan doubles down on suppression as (he) loses ground amid growing economic pressure in the country," Seren Selvin Korkmaz of Istanbul-based think tank IstanPol Institute commented.
"#Kaftancioglu is a rising figure within the #CHP and frequent government target ... The (ruling AKP party) tries to take revenge of losing Istanbul by sending her to prison."
Kaftancioglu vowed not to give in when she was convicted in 2019.
"They think they can scare us but we will continue to speak," she said back then.
Among the tweets used by the prosecution against Kaftancioglu was one in which she criticised the death of a 14-year-old boy hit by a tear gas grenade during the mass "Gezi Park" protests of 2013.
The latest ruling comes on the heels of a life sentence handed by an Istanbul court to another Erdogan critic and activist, Osman Kavala, last month.
A leading figure in Turkey's civil society, the 64-year-old Kavala was accused of attempting to topple Erdogan's government by financing the 2013 protests.