The opposition Republican People's Party (CHP) is preoccupied with retaining its ranks, while the splinter New Party (YP) is working to broaden its voter base.

The YP managed to attract a majority of CHP lawmakers after its chair, Özgür Özel, was replaced by his predecessor, Kemal Kılıçdaroğlu, in May. However, the CHP's mayors are apparently unwilling to switch their allegiance to Özel, who often boasts that he gave the party an unprecedented boost in the 2024 municipal elections.

Several mayors remain undecided, while others were quick to side with Özel. The YP claims that at least 200 mayors are ready to join the party, but that has not been the case in the two weeks since it was founded. So far, the mayors of 157 municipalities have joined the YP, although most represent small district municipalities, with the exceptions of the Denizli Metropolitan Municipality and the Manisa Metropolitan Municipality, the latter in Özel's hometown. Cemil Tugay, the mayor of the CHP stronghold of İzmir, Türkiye's third-largest city, quit the party after Kılıçdaroğlu was reinstated but has remained independent since then. Media reports claim that he may join the ruling Justice and Development Party (AK Party). According to a report by the Sabah newspaper on Monday, the CHP will soon convene a meeting of its mayors to emphasize party unity.