Human Rights Watch warned on Saturday that Erdoğan’s government was undermining Turkish democracy with “abusive tactics” against the CHP.
Erdoğan has led Turkey since 2003, as prime minister and then as president, and Özel has accused his AK party of pursuing a strategy to “eliminate its rivals”.
The 72-year-old leader can only run for president again if he calls early elections before 2028 or changes the constitution.
Justice Minister Akin Gürlek said earlier this week that the appeal court ruling “reinforces our citizens’ trust in democracy”.
The decision overturned a 2025 ruling by a lower court that threw out allegations of vote buying during the CHP primary in which Özel became opposition leader.
The ruling also means the party’s entire executive is replaced, and it is thought its decisions are no longer recognised.