ANKARA, Turkey — The deposed leader of Turkey’s main opposition on Tuesday announced plans to establish a new political party to challenge President Recep Tayyip Erdogan.

The announcement came months after Ozgur Ozel was removed from his post as leader of the Republican People’s Party, or CHP, by a court order — a ruling critics say was a politically motivated effort to weaken the opposition. His ouster, and the reinstatement of the party’s former and unpopular leader, sparked outrage among many CHP supporters.

“We are establishing our new party by taking the first step together with the deputies chosen by our nation,” Ozel said in a speech to fellow CHP lawmakers and other officials in parliament. “These are the determined steps of a march toward governing Turkey.”

Reports have said the new political movement, expected to be called Yeni Parti or New Party, would be formally launched later this week.

Many of the CHP’s 135 legislators in the 600‑seat parliament were expected to defect from the CHP to join the new party, and Ozel said it would become the parliament’s main opposition party “by a wide margin.”

In May, an appeals court — citing alleged irregularities — annulled a 2023 party congress vote that appointed Ozel as CHP chair. The decision reinstated his predecessor, Kemal Kilicdaroglu.

Ozel had succeeded the 77‑year‑old Kilicdaroglu after 13 years of what many analysts described as ineffective opposition to Erdogan.

The 51-year-old has framed the court case as the latest legal attack on the CHP. Criminal investigations across the country — mostly alleging corruption in CHP‑run municipalities — have led to hundreds of elected officials and party members being detained.

Among them is Ekrem Imamoglu, the mayor of Istanbul, who is widely considered the strongest potential challenger to Erdogan. Imamoglu has been imprisoned since March last year and faces multiple criminal cases that could result in decades-long sentences.

The government insists that Turkey’s courts are impartial and act independently of political pressure.

Erdogan, who has ruled Turkey for more than two decades first as prime minister and later president, has rejected claims of a government intervention in the judiciary, calling the legal case that led to Ozel’s ouster an internal dispute within the CHP.

Under Ozel’s leadership, the CHP delivered a significant blow to Erdogan’s ruling party in the 2024 municipal elections, gaining several cities and strengthening its hold on key municipalities it first won five years earlier, including Istanbul and Ankara.