TEHRAN: Iran's state television is to air debates by candidates competing in the June presidential election, the broadcaster's chief Ezatollah Zarghami was quoted as saying by local media on Thursday.

"Six attractive televised debates are on the broadcaster's electoral agenda," Zarghami said, vowing "fairness" in coverage by his organisation which has a monopoly on broadcasting in Iran.

Such debates are not unprecedented in Iran, but Iranian politicians rarely take each other on face-to-face in public despite their differences.

Incumbent President Mahmoud Ahmadinejad, who has faced mounting criticism in Iran mainly over his handling of the economy, has welcomed the plan.

Zarghami did not say when the debates would be broadcast but campaigning for the June 12 election begins on May 22 after a conservative electoral watchdog unveils the list of candidates allowed to stand.

Zarghami's comments follow complaints of bias by state television in favour of Ahmadinejad, who is seeking re-election.

Other leading hopefuls include former prime minister Mir Hossein Mousavi, ex-parliament speaker Mehdi Karroubi and former Revolutionary Guards head, Mohsen Rezai -- all fiercely critical of Ahmadinejad.

Earlier this month about 100 Mousavi supporters staged a protest at what they called the "electoral campaign in favour of Ahmadinejad on TV and radio" outside the state broadcasting centre in Tehran.

Iran has more than 20 state-run radio and television channels, with the head of broadcasting appointed by supreme leader Ayatollah Ali Khamenei. No private broadcasters are authorised.

State media gives comprehensive coverage of Ahmadinejad's tours around the country and to his speeches, leading to accusations that he was using them as election rallies even though formal campaigning has not yet begun