Ozgur Ozel, Turkey's main opposition leader, announced on Tuesday that he would resign from the party and form a new one.
The Republican People's Party, known by its Turkish-language acronym CHP, was founded by Mustafa Kemal Ataturk and is the main opposition to Turkish President Recep Tayyip Erdogan.
Most CHP voters and parliamentarians are expected to follow Ozel to the unnamed new party, after a court in May stripped him of his title as chairman by annulling the CHP's 2023 congress.
Ozel, who has not yet given his new party a name, had been stripped of his title of CHP chairman by a controversial May court ruling that annulled the party's 2023 congress.
The opposition's deepening crisis, including the jailing of hundreds of its elected municipal officials and members since late 2024, is seen as a test of Turkey's democracy and could boost Erdogan's prospects of extending his more than two-decade rule in elections to be held by May 2028.
'A new begining'
In a fiery speech in parliament, Ozel said his team's resignation from the CHP did not mean they were succumbing to political pressure but that they were embarking on a new kind of opposition to Erdogan.
"Today, we are on the brink of a sad farewell that has become inevitable and whose time has come. However, we would like to share with the people that we carry the hope of a new beginning," Ozel told more than 80 CHP lawmakers.
The lawmakers and other supporters cheered and chanted "Free Turkey, free future" — in a reference to Ozel's name, which means "free" in Turkish.
"Finally," said one supporter after the speech, declining to give her name, adding: "We don't have time to lose with pointless fights within the party."
Crackdown against CHP
The May court decision had cited irregularities in the CHP congress and reinstated as chairman Kemal Kilicdaroglu, the divisive and less popular former leader who lost to Erdogan in a 2023 presidential vote.
Ozel and critics say the court ruling and a broader legal crackdown on the CHP amount to a politically motivated "coup." The government rejects such accusations and says the judiciary is independent.
The crackdown has rattled financial markets and fueled concerns about the rule of law and an autocratic slide in NATO member Turkey.
Ekrem Imamoglu, who is Erdogan's main political rival and mayor of Istanbul, has now been in prison for more than a year.
Ozel said he would not "leave behind" Imamoglu or Ankara Mayor Mansur Yavas, who is seen as another potential challenger to Erdogan.
Election calculus
Analysts said the new party could benefit Erdogan and his ruling AK Party by splitting the opposition camp and undermining their solidarity.
"This picture can only change if the new party can create a very strong societal response and transform into the main hub of the opposition," said Murat Gezici, chairman of pollster Gezici.
"However, in the short and medium-term, the political arithmetic works in favor of Erdogan and the AK Party."
Under the constitution, Erdogan can only run again for president if the election is called earlier than May 2028. This requires a three-fifths majority of parliament, or 360 of 600 lawmakers, but the AK Party and its allies currently only have 328 seats.
The centrist CHP has 135 lawmakers, most of whom are expected to shift to Ozel's new party. The leftist pro-Kurdish DEM Party and its allies have 63, the Turkish nationalist IYI Party has 29, smaller opposition parties have 26, and there are also 11 independents.