A cardiac surgeon, a former mayor of Tehran and a cleric implicated in the execution of political prisoners are among the six candidates approved by officials to run in Iran’s election on Friday to replace the president who died in a helicopter crash last month.

The candidates have renounced Iran’s hijab enforcement. They’ve addressed American sanctions that have contributed to the country’s flailing economy, and openly criticized the government during a series of debates, an unusual move in Iranian politics. Still, voter apathy in the country is high and divisions among conservative leaders make predicting the outcome difficult.

Though Iran’s supreme leader, Ali Khamenei, has ultimate authority over key state matters, the president sets domestic policy and can influence foreign policy.

Iran’s Guardian Council, a committee of 12 jurists and clerics, whittled an initial list of 80 presidential candidates down to six, disqualifying seven women and a former president and many other government officials. Four candidates are still in the race.

Two of the candidates — Amirhossein Ghazizadeh Hashemi and Alireza Zakani — dropped out of the race to consolidate the conservative vote. If no candidate wins a majority on Friday, a runoff election will be held on July 5 between the top two winners.

The latest polls, published by the conservative, government-run Imam Sadiq University earlier this week showed Dr. Masoud Pezeshkian leading with approximately 24.4 percent of votes, Mohammad Baqer Ghalibaf at 23.4 percent and Saeed Jalili at 21.5 percent. The other candidates each had less than 5 percent of the vote and nearly a fifth of voters were undecided.