A Turkish court on Friday kept civil society leader Osman Kavala in jail despite Western pressure and the risk the case could further harm Ankara's relations with Europe.

The hearing in Istanbul was the first since President Recep Tayyip Erdogan threatened to expel 10 Western ambassadors who called for Kavala's release.

The 64-year-old civil society leader and businessman, who has languished in jail without conviction for more than four years, is accused of financing 2013 anti-government protests and playing a role in the 2016 coup attempt.

If convicted, he could face a life term without the possibility of parole.

Kavala, who denies the charges, snubbed the hearing on Friday after his case sparked a diplomatic standoff last month when the 10 embassies -- including the US, France and Germany -- said in a highly unusual declaration that his continued detention "cast a shadow" over Turkey's democracy and judicial system.

Philanthropist Osman Kavala has been kept in jail without conviction for four years
Philanthropist Osman Kavala has been kept in jail without conviction for four years Anadolu Culture Center via AFP / Handout

Erdogan accused the diplomats of trying to "teach a lesson" to Turkey and threatened to expel them.

Western diplomats, including from countries whose envoys had been threatened with expulsion, were in court Friday, as well as several opposition lawmakers and Kavala's wife Ayse Bugra, a renowned academic.

"I don't know how many hearings I have attended for four years. These hearings always end with the exact same words, same sentences: continuation of detention," Ayse Bugra told journalists outside the court.

"Prosecutors do not ask any question to a suspect about whom they prepare indictments which include very heavy expressions. This is not normal. This fits neither the norms of universal law nor human rights."

The next hearing is scheduled for January 17.

Supporters of jailed civil society leader Osman Kavala rally outside the court as the trial resumes
Supporters of jailed civil society leader Osman Kavala rally outside the court as the trial resumes AFP / Ozan KOSE

The philanthropist has become a symbol for his supporters of the sweeping crackdown Erdogan unleashed after the failed coup.

The hearing also came with Erdogan facing one of the toughest economic tests of his rule since 2003 and the Turkish lira tumbling to record lows against the dollar.

The lira was trading at 12.3 to the dollar after the decision, losing almost three percent in value.

The hearing in Istanbul was the first since President Recep Tayyip Erdogan threatened to expel 10 Western ambassadors who called for Kavala's release
The hearing in Istanbul was the first since President Recep Tayyip Erdogan threatened to expel 10 Western ambassadors who called for Kavala's release AFP / Ozan KOSE

Kavala's case could prompt the Council of Europe human rights watchdog to launch its first disciplinary hearings against Turkey at a four-day meeting beginning on Tuesday -- an infringement procedure that has only been used once before in the court's history.

The watchdog has issued a final warning to Turkey to comply with a 2019 European Court of Human Rights order to release Kavala pending trial.

"Today was a big chance for Turkey to allay concerns over the independence of Turkish courts," Kavala's lawyer Tolga Aytore told reporters.

"It was a chance to show politics does not interfere in the judiciary. I believe the judiciary missed this chance."

In an open letter published on Friday, Amnesty International called on the heads of state to resort to the rarely used procedure against Turkey.

"Turkey's justifications for refusing to free Osman Kavala from prison have run out of steam," Amnesty's Europe Director Nils Muiznieks said.

Ankara's refusal to implement the European court's binding ruling "represents a serious threat to the integrity of the European human rights system".

In an interview with AFP this month, presidential spokesman Ibrahim Kalin refused to speculate on the outcome of the infringement procedures.

"I hope they (the Council of Europe) take all the facts into consideration and respect rule of law in this country... when they make a decision," he said.

Erdogan has often compared Kavala to Hungarian-born US financier George Soros and called him "Soros leftover" in October.

"The president's insulting and defamatory statements against a person who is not convicted and whose trial is ongoing constitutes an attack on human dignity," Kavala said in a statement.

Kavala, who previously attended the hearings in Istanbul's main court via video-link from his cell in Silivri on the city's outskirts, said he had lost faith in a fair trial.

Speaking to AFP from his jail cell last month, Kavala said he felt like a tool in Erdogan's attempts to blame a foreign plot for domestic opposition to his nearly two-decade rule.

He was acquitted of the Gezi charges in February 2020, only to be re-arrested before he could return home and thrown back in jail over alleged links to the coup plot.