Former Iranian president Mahmoud Ahmadinejad, whose 2009 re-election prompted mass unrest over alleged vote rigging, has called for "free" presidential and parliamentary elections in an open letter to Supreme Leader Ayatollah Ali Khamenei.
Khamenei backed Ahmadinejad after his return to power kicked off protests in which dozens of people were killed and hundreds arrested, rattling the ruling theocracy, before security forces led by the elite Revolutionary Guards stamped out the unrest.
But a rift developed between the two in 2011 when Khamenei, who has the ultimate say over all policy in the Islamic Republic, reversed Ahmadinejad's dismissal of the minister of intelligence and suggested he had overstepped his authority.
Ahmadinejad, a brash, populist hardliner while in office, could not run in the 2013 election as he had served the maximum two consecutive terms. He was succeeded by pragmatist Hassan Rouhani, who won election by landslide then and again last year.