The Turkish parliament voted by a two-thirds majority Friday in favour of a constitutional amendment lifting the immunity from prosecution of 138 members of parliament, including nearly all the pro-Kurdish legislators.
The two-thirds majority means there is no need for a referendum. The move is seen a victory for President Recep Tayyip Erdogan, who has been calling for members of parliament from the pro-Kurdish Peoples' Democratic Party (HDP) to lose their immunity.
Voting in favour were 376 members of the 550-seat house, while 140 were against, in the decisive round. Some members abstained.
Erdogan sees the HDP as a rival for votes in the mostly-Kurdish south-east of the country. He accuses its parliamentarians of being tied to the banned Kurdistan Workers' Party (PKK).
The HDP has strongly denied charges it is a wing of the PKK and insists Erdogan is waging a "totalitarian attack" against the party, aiming to consolidate his own grip on power.
The party has vowed to wage legal battles against the immunity bill, saying it would take the matter to the European Court for Human Rights.
The chief of the HDP, Selahattin Demirtas, told a press conference he views the move as an effort for the presidency to move towards a "dictatorship," vowing that "our fight has only begun."
He told Cumhuriyet newspaper, an opposition daily, that party members could now be placed in custody.
"There's no obstacle to our detention, for Erdogan and the courts. If he gets this chance, he would like to do so, with the help of the judiciary which is in his hands," said Demirtas, one of the 50 members of HDP who will lose their immunity. The party has 59 seats.
The amendment must still be published in the official gazette.
Erdogan this week took a separate step forward in ensuring he is the dominant force without rival in Turkish politics, after his ruling Justice and Development Party (AKP) chose a long-time loyalist as its new chief.
Binali Yildirim will be confirmed as the new party leader at a meeting on Sunday, replacing Ahmet Davutoglu. The AKP is touting the new leader as being completely in-line with Erdogan and someone who will implement his plan of action.
Specifically, Erdogan is seeking to change the constitution to empower the presidency, a move critics say will weaken parliament and deplete the political system of checks and balances. There have already been moves against judges and police officers.
The AKP, of which Erdogan is a founder, won 317 seats in the last election. To get the two-thirds majority on the immunity vote, the AKP appears to have relied on hardline Turkish nationalists.
The decision by the Turkish parliament is "a matter of serious concern," top EU officials said in a statement.
"In line with relevant international recommendations, immunity must apply to all on a non-discriminatory basis and decisions on lifting immunity must be based on the merits of each specific case ... and not subject to any political considerations," EU foreign policy chief Federica Mogherini and EU Enlargement Commissioner Johannes Hahn said.
"A restrictive interpretation of the legal framework and the constitution in particular continue to pose a risk to the freedom of expression of members of parliament in Turkey," they added.
They also noted that "any alleged wrongdoing or crime committed by members of parliament should be subject to due process."
German Chancellor Angela Merkel said that she would raise the decision in talks with Erdogan on Monday.
Turkey has a history of banning Kurdish members of parliament. Last year, the ceasefire between the state and the PKK collapsed and violence is wrecking the mostly-Kurdish south-east of the country.
The 138 members who now are open to prosecution are from all the four parties in parliament and have police dossiers opened against them. The next steps remain unclear, as prosecutors will now have to decide which cases to pursue.