Iran's interior ministry said on Thursday there would be no live debates in the run-up to next month's presidential election.
"Based on a decision by the Election Campaign Monitoring Commission, the election debates of the candidates will be broadcast pre-recorded," interior ministry spokesman Seyed Salman Samani said.President Hassan Rouhani, who has registered to run for a second term in the May 19 election, called for the decision to be reviewed.
"I don't want to interfere... but I would like the election headquarters to review these discussions," he said, according to state news agency IRNA.
The election commission also issued guidelines for the debates, telling candidates they are not allowed to "blacken the image of the country... or the actions of the executive, administrative, legislative or judicial bodies".
Live debates have been a hugely popular feature of the last two elections in 2009 and 2013, with many analysts saying Rouhani's performance was key to his surprise victory last time.
Conservative candidate Alireza Zakani slammed the ban, saying it would "seriously damage transparency".
The heated TV debates in 2009 between hardline president Mahmoud Ahmadinejad and his reformist opponents fired up the electorate and were seen as partly responsible for the post-election unrest that occurred when Ahmadinejad was re-elected amid allegations of vote-rigging.
More than 1,600 people have signed up to run in the election on May 19.
That number will be whittled down by the conservative-dominated Guardian Council in the coming days, with around half-a-dozen candidates normally permitted to stand.