Turkey's main pro-Kurdish party will elect two new leaders on Sunday, one of whom will replace its charismatic jailed co-chief Selahattin Demirtas, ahead of elections in 2019.
Demirtas, the best-known face of the left-wing Peoples' Democratic Party (HDP), has been behind bars since November 2016, detained on terrorism charges, and faces a possible 142-year prison sentence.
In January, he appeared before an Istanbul court on separate charges of insulting President Recep Tayyip Erdogan.
Whoever succeeds Demirtas will lead a party isolated in parliament and be aware that many of the group's beliefs will likely clash with Erdogan.
The HDP has regularly accused the president of "authoritarianism", many of its MPs and members have been detained, and it opposes Turkey's current offensive against a Kurdish militia in northern Syria.
The HDP has described the operation against the People's Protection Units (YPG) as an "invasion" that targets Kurds "as a people", but Ankara views the YPG as a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK), which has fought the Turkish state for decades.
The YPG militia was the principle ally of the United States in the fight against the Islamic State group in Syria.
At the HDP congress on Sunday, the party will choose a man to replace Demirtas and a woman to replace its other co-leader Serpil Kemalbay, who took over from another incarcerated former leader, Figen Yuksekdag.
The party says it always has a woman and man in leadership positions in the interests of equality.
Sezai Temelli, a former MP, and Pervin Buldan, who is serving in parliament, have been nominated to become the new co-leaders, the party said this week.
They will attempt to lead the party to a fresh start ahead of general and presidential elections in November 2019, aware they are operating in an increasingly restrictive political climate.
On Thursday, MEPs in the European parliament criticised the "deterioration of freedoms and fundamental rights and the rule of law in Turkey".
It called on Ankara to scrap emergency powers brought in after the failed July 2016 coup, which members said were being used to stifle "legitimate and peaceful opposition" and a free press.
Since the attempted putsch, more than 140,000 people have been suspended or sacked over alleged links to coup-plotters.
More than 160 media outlets have also been closed.
Demirtas, dubbed by some the "Kurdish Obama" after the ex-US president, came to prominence after leading the HDP into parliament for the first time in June 2015.
Analysts say his success was because he appealed to voters outside the Kurdish minority including non-Kurdish leftists and liberals.
But Demirtas and Yuksekdag were among a dozen HDP MPs detained in November 2016 as part of a crackdown that followed the attempted coup. Nine HDP lawmakers remain in jail.
Yuksekdag was stripped of her lawmaker status in February 2017 and stepped down as co-leader in May last year.
Last month, Demirtas, 44, said he would step down from his post, fearing he would likely remain imprisoned.
"Even if Mr Demirtas... is or isn't the co-leader, he is an important figure in political life and he will continue to be involved in politics under any condition," HDP's spokesman Ayhan Bilgen told AFP.
Demirtas faces multiple legal cases including accusations he has links to the PKK, which is also blacklisted as a terror group by Ankara's Western allies.
Since entering parliament under Demirtas's leadership, the HDP has come under heavy pressure with seven of its lawmakers losing their MP status. The party had 59 MPs in late 2015.
"This atmosphere (of pressure) is so widespread, so systematic, so rooted, that we are conscious that we have to do politics under these conditions," said Bilgen, who spent eight months in pre-trial detention last year over alleged PKK links.
The party says some 3,300 HDP members have been arrested since the collapse of a two-year ceasefire between the Turkish state and the PKK in July 2015.
Since Turkey's offensive in Syria against the YPG began in January, there have been more arrests. The HDP says 368 of its members had been detained over their opposition to the fighting.
The authorities accuse many of them of spreading "terror propaganda".
On Friday arrest warrants were also issued for 17 people, including Kemalbay, over calls for protests against Ankara's Syria operation, state media reported.