Iran’s short, intense presidential campaign kicks off Friday with the first televised debate featuring six candidates in a race widely seen as a referendum on whether Iranians feel they have benefited from the nuclear deal that took effect last year.

The May 19 vote will see the moderate incumbent, President Hassan Rouhani, facing off against conservative and reformist challengers, including a hard-line cleric with backing from the country’s religious establishment.

Iran’s influential Guardian Council, a body of senior clerics and jurists appointed by the supreme leader, vets the candidates each election. This year, Rouhani’s approved challengers include the hard-line mayor of Tehran, Mohammad Bagher Ghalibaf; a conservative former culture minister, Mostafa Mirsalim; Vice President Eshaq Jahangiri, a moderate; and former vice president Mostafa Hashemitaba, a reformist.

Also on the list, which was whittled down from the 1,600 or so who initially registered, is Ebrahim Raisi, a confidant of Iran’s supreme leader, Ayatollah Ali Khamenei, and the man now viewed as Rouhani’s main rival. When the Guardian Council weighed in last week, it disqualified former president and populist firebrand Mahmoud Ahmadinejad.