Turkey has put 108 Kurdish politicians on trial in what critics say is politically motivated “revenge” for their alleged roles in deadly protests in 2014 sparked by the Isis takeover of the Syrian border town of Kobani.

Proceedings on Monday got off to a tense start when defence lawyers walked out of the Ankara courtroom, alleging that some of their colleagues had not been allowed in for “arbitrary and unlawful” reasons.

The current and former members of the pro-Kurdish Peoples’ Democratic party (HDP) – 28 of whom are already in prison, including the former co-chair Selahattin Demirtaş – are charged with offences including homicide and “attacking the integrity of the state”. Prosecutors are seeking multiple life sentences and thousands of years in prison.

HDP says the Turkish police are to blame for the deadly violence.

Thirty-seven people died in protests across the mainly Kurdish south-east of the country triggered by the Isis assault on Kobani, where the vast scale of the fighting was clearly visible from the Turkish side of the border. Many in the country’s Kurdish community accused the Turkish army of standing by and allowing a massacre.

Smaller protests grew after the HDP tweeted an “urgent call” for people to take to the streets and demonstrate.

“For calling on people to protest, our members are now being accused of terrorism, and also of murder of those who died,” the HDP said in a statement as the mass trial got under way.

“This is a revenge trial,” said HDP’s co-chair Mithat Sancar.

Isis was driven out of Kobani in January 2015 by US-backed Syrian Kurdish fighters that Turkey views as terrorists linked to its own Kurdistan Workers’ party (PKK) insurgency.

The HDP is also under attack by Ankara over alleged links to the PKK: all but two of dozens of HDP mayors have been removed from office and replaced with government-appointed trustees in the past two years, and last month state prosecutors filed a case to close down the party altogether. The suit would also bar nearly 700 of HDP’s members from playing a role in politics for five years.

The HDP defendants in Monday’s opening trial refused to respond to questions by the judge during the identification process without their lawyers present, saying their right to defence was being violated. Defendants connected via video link tapped their cameras and clapped in solidarity, a statement from the party said.

All the defence lawyers were subsequently allowed in.

“Even though we are sitting in the defendant’s seat, we represent the people’s will,” said Demirtaş, a two-time election rival to Turkey’s president, Recep Tayyip Erdoğan, and one of the country’s most prominent politicians.

The 48-year-old has been in jail since 2016 and faces multiple trials on terror-related charges that western governments view as part of Erdoğan’s crackdown on political dissent. In December, the European court of human rights ruled his detention was unlawful.

Agencies contributed to this report