TEHRAN, Iran (AP) — The only reformist candidate in Iran's upcoming presidential election dropped out of the race Wednesday on the last day of campaigning, state media reported, likely trying to boost the chances of a moderate candidate.

Mohsen Mehralizadeh, 64, resigned in a letter to Iran's Interior Ministry, which runs elections in the Islamic Republic, the state-run IRNA news agency reported. Such dropouts are common in Iranian presidential elections in order to boost the chances of similar candidates.

Mehralizadeh's departure likely will boost former Central Bank chief Abdolnasser Hemmati, who has been running as a moderate and as a stand-in for President Hassan Rouhani, who is term limited from running again.

Mehralizadeh served as governor in two Iranian provinces, as the vice president in charge of physical education under reformist President Mohammad Khatami and as a deputy in the Atomic Energy Organization of Iran, which runs the country’s civilian nuclear program. He came in last place in Iran’s 2005 election, but found himself barred from running in 2015.

The announcement Wednesday leaves six candidates in the race. Polling and analysts indicate Hemmati lags behind the country’s hard-line judiciary chief, Ebrahim Raisi, the campaign's front-runner long cultivated by Iran’s Supreme Leader Ayatollah Ali Khamenei. Other hard-line candidates may drop out Wednesday to lend their support to Raisi.

Within Iran, candidates exist on a political spectrum that broadly includes hard-liners who want to expand Iran’s nuclear program and confront the world, moderates who hold onto the status quo and reformists who want to change the theocracy from within.