Turkey's main opposition Republican People's Party (CHP) has nominated Erdoğan Toprak for the post of parliament speaker.
Toprak, a onetime youth and sports minister, is a lawmaker from the Istanbul province.
Speaking to reporters on Wednesday, Toprak said that the parliament will represent Turkey.
"I put myself before the conscience of 600 parliamentarians under this roof," he added.
The opposition Good (IYI) Party also nominated Hayrettin Nuhoğlu for the post ahead of Thursday's elections.
Nuhoğlu, born in 1953, is also an Istanbul lawmaker.
The ruling Justice and Development (AK) Party's candidate for parliament speaker is Binali Yıldırım, who served as prime minister until this week, when the post was abolished under constitutional changes.
The Nationalist Movement Party (MHP) has announced it will support the AK Party candidate.
In the first two rounds of voting for speaker in the parliament, at least 401 out of 600 deputies' votes are needed to win.
In a third round of voting, a minimum of 301 votes is needed. If a fourth round is necessary, the candidate with the largest number of votes is elected.
The AK Party holds 290 seats in parliament, while the Republican People's Party (CHP) has 144 seats, the Peoples' Democratic Party (HDP) 67 seats, the MHP 49, IYI Party 42, Felicity (Saadet) Party 2, Democrat Party (DP) 1, and Grand Unity Party (BBP) 1.
