Turkey's state prosecutor filed a case with the constitutional court demanding the closure of the pro-Kurdish Peoples' Democratic Party (HDP) party, state-owned Anadolu news agency reported on Wednesday.
The move came after a years-long crackdown on the HDP, the third largest party in parliament. The crackdown recently intensified with nationalist allies of President Tayyip Erdogan's AK Party (AKP) calling for it to be banned over what they say are links to Kurdish militants.
The indictment said HDP members, through their statements and actions, aimed to break the unity of the state with the Turkish people, Anadolu said.
The government accuses the HDP of links to the Kurdistan Workers Party (PKK), which is designated a terrorist group by Turkey, the United States and European Union. The HDP denies such ties.
The PKK has fought an insurgency against the state in mainly Kurdish southeast Turkey since 1984. More than 40,000 people have been killed in the conflict.
Earlier on Wednesday Turkey's parliament stripped a prominent HDP deputy of his seat over a criminal conviction for spreading "terrorist propaganda" in a social media post.