There will be no bargaining over a new constitution for Turkey that could enhance the powers of the president, the prime minister said Sunday, adding that the government will seek to put the matter to a referendum.

The ruling Justice and Development Party, or AK Party, will have the support of all 317 deputies for a new charter and will look for an additional 13 votes from the opposition that are needed to take the draft to a referendum, Ahmet Davutoglu told the broadcasting organization A Haber.

A cross-party commission charged with drafting a new constitution collapsed last month after the main opposition bloc pulled out over attempts by the AK Party to change Turkey from a parliamentary to a presidential system.

“All 317 AK Party lawmakers will do what’s necessary. The constitution is not up for bargaining. It’s a matter of principles,” Davutoglu said. “We will find the 330 [votes] and take it to a referendum. Our people will have a constitution embraced by all, and the [current] charter will be consigned.”

Senior AK Party officials said last week that the party was working on its proposals despite the opposition’s resistance, plans that could hand President Recep Tayyip Erdogan powers to draft legislation directly and pick ministers.

The AK Party has broad support for overhauling the constitution, which dates to the period after the 1980 military coup and has been amended repeatedly. But there are wide divergences over what a new charter should look like.

Erdogan wants the charter to transform the presidency from a largely ceremonial post to an executive one with expansive powers.

Davutoglu said parliament will begin debate on revoking the parliamentary immunity for lawmakers from the opposition Peoples’ Democratic Party (HDP), which has Kurdish roots, after budget talks conclude Wednesday.

The Justice Ministry last week submitted a request for the assembly to scrap the protection from the prosecution of five HDP lawmakers, including the party’s co-leaders, Selahattin Demirtas and Figen Yuksekdag, after repeated calls for such a move by Erdogan.

The ultra-right Nationalist Movement Party, parliament’s fourth-biggest grouping with 40 seats, has signaled its support for stripping Demirtas and the others of their immunity.

Demirtas told reporters that the AK Party was using the issue to tap nationalist support amid clashes between security forces and Kurdish militants in Turkey’s restive southeast.

“The government has raised the issue of our immunity before, but this time they appear serious,” he said. “They want to scapegoat us. We don’t want this to happen, because not only will it hurt our party but all of Turkish society and its democracy.”

Even if parliament lifts the lawmakers’ immunity, the HDP will retain its 59 seats until any prosecution is complete, which could take years, Demirtas said.

He also reiterated the HDP’s opposition to an executive presidency, saying it would make the government more autocratic.

Opposition parties want the new charter to focus on minority rights and democratic freedoms and fear that an executive presidency would consolidate too much power in the hands of one man.

— Reuters