The decision came after judicial and constitutional commissions from the parliament prepared a report on 56-year-old Leyla Zana, asking for her dismissal.
Of 324 legislators in attendance, 302 voted in favor of dismissing the Kurdish politician from the Turkish legislature, while 22 opposed the measure, Turkish-language NTV television news channel reported on Friday.
Parliamentary sources said Zana missed 212 consecutive parliament days between October 1, 2016 and April 30, 2017.
Zana had taken the oath on November 17, 2015 while saying in Kurdish, “With the hope of an honorable and lasting peace.”
She had also finished it by changing its official wording of “Turkish people” to “people of Turkey,” leading the speaker to rule her oath invalid.
“Leyla Zana being stripped of her lawmaker status is void before our people,” the HDP said in a tweet following the decision.
It added, “Leyla Zana is the sound of peace, the will of the people, our member of parliament.”
Zana rose to prominence in 1991, when she spoke in Kurdish at her oath-swearing ceremony in Turkey’s parliament.
“I take this oath for the brotherhood between the Turkish people and the Kurdish people,” she said, earning herself a 10-year prison term.
The Turkish parliament has harsh punishments for speaking in Kurdish or using the word "Kurdistan" in the legislature.
On November 4, 2017, the Diyarbakir 5th High Criminal Court found opposition HDP lawmaker Selma Irmak guilty of “leading an armed terrorist organization” and “carrying out propaganda activities for terrorist purposes.”
On December 26, 2016, Turkish security forces arrested Aysel Tugluk, a senior official of the HDP, in the capital Ankara, as part of an investigation launched by the Diyarbakir Chief Public Prosecutor's Office against the Kurdistan Workers' Party (PKK) militant group and the Kurdistan Communities Union (KCK), an alliance of pro-Kurdish groups.
In November last year, 13 HDP legislators were arrested over alleged links to the PKK.
Party leaders Selahattin Demirtas and Figen Yuksekdag remain in custody along with eight others, pending trial on terrorism-related charges.
On January 18 last year, Turkish prosecutors announced they were seeking a 142-year prison sentence for Demirtas.