President Mahmoud Ahmadinejad said on Wednesday plans to segregate male and female students at Iranian universities must be halted, drawing another battle line in his ongoing tussle with traditionalist rivals.

As part of a wider drive to assert Islamic values at Iran's colleges, the minister in charge of higher education has said male and female students must be taught separately when classes begin again in September. But in a message on his website, Ahmadinejad said the policy must be stopped.

"It has been heard that in some universities, classes and disciplines are being segregated without considering the coincidences," he said on the website dolat.ir.

"Urgent action is required to prevent these superficial and non-scholarly actions."

Ahmadinejad's opposition to sex segregation will further alienate his conservative and religious critics who have becoming increasingly outspoken against him and his circle of advisers they say belong to a "deviant current" that puts secular nationalism ahead of Islam, posing a potential threat to Iran's clerical rule.

Seen as an extreme hardliner by many in the West due to his comments against Israel and Iran's refusal to curb its nuclear programme, at home the populist Ahmadinejad is outflanked on the right by ultra-conservatives who consider he has not adhered closely enough to the values of the Islamic Revolution.

Science Research and Technology Minister Kamran Daneshjou has said Iran will separate sexes at universities from the start of term on Sept. 23.

"Following the implementation of the Hijab (Islamic dress) and Chastity Plan, university classes will be separated. If there is not the facility to separate the classes, students will sit in separate rows," he said, according to IRAN daily.

More than half of Iran's 3.7 million students are women, studying alongside their male classmates, and education has become a focus for conservatives who want to head off what they consider corrosive western values among the youth born long after the 1979 Islamic revolution.

On the instruction of Supreme Leader Ayatollah Ali Khamenei, Iran is already reviewing the curricula of certain subjects deemed too western, including law, philosophy, psychology and political sciences, to ensure they do not run counter to Islamic teachings.

Ahmad Khatami, an influential conservative cleric who regularly leads Friday prayers in Tehran, came out in favour of segregation.

"With what logic should a head of a Tehran university be reprimanded for separating the classes of women and men? We should give him a medal."

In a television interview last year, Ahmadinejad said women who fail to cover their hair completely in public should not be harassed by the police.

Nevertheless, the enforcement of the Islamic dress code has been stricter since his election in 2005, with 'morality police' staging annual crackdowns against women dressed too immodestly.

His chief of staff, Esfandiar Rahim-Mashaie, the main target of opponents of the so-called "deviant current", has publicly stated that women still face "oppression" in Iran.

Khamenei has called the infighting between rival factions of the ruling elite ahead of parliamentary election a propaganda gift to Iran's foreign enemies.