The court cited procedural misconduct from decision critics on Tuesday, which overturned Turkey’s major opposition meetings in Istanbul province and viewed it as an escalating campaign to weaken the party.
The ruling against the Republican People’s Party (CHP) led to the firing of Istanbul Chairman Özgürçelik and other state managers.
A provisional committee has been appointed to oversee the party’s Istanbul branch.
The decision allegedly a procedural violation following the legal challenges attempting to override the CHP’s Istanbul meeting on October 8th.
It will come weeks before another court in Ankara takes over a similar case targeting the main CHP assembly in 2023.
The ruling against the CHP in that case could bring back former leader Kemal Kirchaloul.
The court’s ruling coincides with an escalating crackdown on local governments managed by the CHP, resulting in a series of arrests beginning in March with Mayor Iklem Imamolu.
A prominent opposition figure, Imamol is widely seen as a major challenger to President Recept Tayyip Erdogan’s two-year rule.
The arrests have been made against allegations of corruption, and CHP strongly denies it.
Imamol’s imprisonment has led to Turkey’s biggest protest for over a decade, with demonstrators denounced a democratic reversal under Erdogan.
Critics argue that the legal action is politically motivated and designed to undermine the CHP’s influence.
The Erdogan government argues that the judiciary operates independently and denys political interference.
“This decision is a blatant blow to our democracy,” CHP’s top MP Ali Mahir Basharur said in a post in X following the ruling on Tuesday.
“We will continue our legal and political struggle against those who try to steal our will through judicial means.”
Özel said the CHP would appeal to the ruling.
Turkey’s leading stock index, BIST100, fell more than 5% after the decision, then recovered the ground to close 3.57% at 10,877 points.
Since 2019, Istanbul and several other major cities have moved to CHP control, with opposition expanding further in last year’s city elections.