Tehran's ultraconservative mayor, Alireza Zakani, announced his withdrawal in a post on social media platform X on Thursday, after earlier denying he was ending his campaign.
Zakani's withdrawal came hours after a statement by the Ministry of Interior confirming the exit of Amirhossein Ghazizadeh-Hashemi, another ultraconservative.
In his post, Zakani urged two other candidates to unite.
Zakani said ultraconservative Saeed Jalili, 58, Iran's former nuclear negotiator, and conservative Mohammad Bagher Ghalibaf, 62, the speaker of the parliament, should "unite and not leave the revolutionary forces' rightful demands unanswered".
Zakani, 58, a veteran of the Iran-Iraq war, has served as Tehran's mayor since August 2021.
In the 2021 presidential election, Zakani left the race to endorse President Ebrahim Raisi.
The death of Raisi in a helicopter crash in May brought forward the election.
Ghazizadeh-Hashemi, who was Raisi's vice-president, "announced his withdrawal to the Ministry of Interior" on Wednesday, the ministry said in a statement.
He ended his campaign without endorsing a specific candidate.
Ghazizadeh-Hashemi, 53, is a medical doctor and a staunch supporter of Raisi's government who also serves as head of the Martyrs' Foundation, tasked with providing support to the families of those killed in service to the country.
In the 2021 presidential election, he secured 3.5 percent of the vote.
"To preserve the unity of the forces of the revolution ... I will withdraw from continuing the path" to the presidential election, Ghazizadeh-Hashemi said in a post on X late Wednesday.
In his message, the vice president urged other conservative and ultraconservative candidates to "also agree" on one candidate to offer a united front.
Along with Jalili and Ghalibaf, those still seeking the presidency are veteran politician Mostafa Pourmohammadi, 64, who is the only cleric in the running, and Massoud Pezeshkian, 69, the oldest candidate and sole reformist, backed by former president Hassan Rouhani.
