The head of Turkey’s leftist, anti-Islamist Peoples’ Democratic Party (HDP) announced this week that he will begin a hunger strike from prison where he is awaiting trial for allegedly supporting terrorists.

Selahattin Demirtaş was arrested along with fellow HDP co-chair Figen Yuksekdag in November after ruling Islamist Justice and Development Party (AKP) legislators voted to strip them both – and other HDP members – of legislative immunity.

The government of President Recep Tayyip Erdogan claims Demirtaş and Yuksekdag have made statements of support to the Kurdistan Workers’ Party (PKK), a U.S.-designated Marxist terrorist organization. The HDP leaders contend, however, that Erdogan is attempting to establish a “caliphate” within Turkey and erode the influence of religious and ethnic minorities to consolidate his own power.

In a message from prison, Demirtaş announced Thursday that he and fellow imprisoned HDP lawmaker Abdullah Zeydan would begin a hunger strike Friday. “We are going on a hunger strike starting from Friday due to the warden’s refusal to engage in dialogue, his practices outside the boundaries of law, his inhumane treatment of other inmates, and the fact that he didn’t take any well-intentioned step towards ending other inmates’ hunger strikes, which have been going on for days,” Demirtaş wrote.

“We invite the public to be sensitive regarding the ongoing hunger strikes and rights violations in prisons,” he added.

At least one other HDP representative who was imprisoned along with party leaders in November has also begun a hunger strike. An HDP representative said they do not know the status of many of their members as the Erdogan government has not given them access to the prisons. “Hunger strikes may have started in jails that we don’t even know about,” the representative, Burcu Çelik, told the newspaper Hurriyet.

The anti-Erdogan newspaper Cumhuriyet published more of the Demirtaş statement in Turkish. “As lawmakers, we have no demands for ourselves,” he wrote. “We engage the hunger strike to draw attention to the problems in the prisons, to remind the Ministry of Justice of its responsibility and in particular to protest the arbitrary practices of the Edirne Prison Director.” The HDP leader is being held in Edirne.

Demirtaş also sent a letter to Erkan Baş of the Turkish Communist Party thanking the nation’s communists for their support. “We… express our greetings to the Turkish socialists who have put forth a stance equivalent to the historical period that determines our future centuries,” Demirtaş wrote.

The Turkish ruling AKP considers itself a right-wing party, with a free market policy platform and opposition to Marxist groups such as the PKK. The AKP is an Islamist party, however, with ties to the Muslim Brotherhood. Under Erdogan’s leadership, the AKP has pioneered the return of the hijab to secular Turkish society, imposing Islamic teachings in schools, and permitting Islamic prayers in the Hagia Sophia basilica.

The HDP has stridently opposed the Islamization of Turkey and embraced both ethnic minorities and religious minorities, sending four Christians into the Turkish parliament in 2015. The HDP has also proposed the radical policy of acknowledging the reality of the Armenian genocide, which Ankara has refused to do since the founding of modern Turkey

Erdogan dismissed the rise of the HDP as a conspiracy designed by then-American President Barack Obama. Due to the overwhelming gains the HDP made in that election, Erdogan dissolved the parliament and called for another round of voting to reestablish AKP dominance.

Following the second parliamentary election, the Turkish legislature voted to strip HDP legislators of their immunity, but not after multiple brawls broke out between AKP and HDP members in the parliament. Turkish police subsequently arrested the HDP leadership and an estimated dozen lawmakers for allegedly aiding terrorists and disseminating terrorist propaganda by opposing the agenda of the AKP.