Ayatollah Ali Khamenei's comments were aimed at easing mounting criticism of President Mahmoud Ahmadinejad, who faces a possible summons to answer questions from a hostile conservative-dominated Parliament, some of whose members have talked of impeaching him.   

"We should try to reduce differences in opinions as much as possible," the 71-year-old cleric told a gathering of senior officers of the Revolutionary Guards in a televised address.   

"Unfortunately in the current situation in the country where one is against another and vice versa, do those who foment these disputes not see how much it makes foreign propaganda machines happy?"   Infighting within the ruling elite has become more apparent since the government crushed opposition protests in the weeks and months after Ahmadinejad's disputed re-election in June 2009, and have intensified over the last three months.   

Ahmadinejad's critics accuse him of being close to what they refer to as a "deviant current" of advisers who promote secular nationalism above Islam, something they see as a threat to Iran's powerful clerical hierarchy.   In his speech, Khamenei said the critics should not be too quick to condemn people who, although they might have differences of opinion, did not intend to overthrow Iran's unique form of Islamic Republic.

"Sometimes a current might want to stand against the Islamic revolution and at that time it is definitely everybody's duty to defend the revolution," he said, citing the tough state response to the "green movement" protests of 2009 as an example.

"But sometimes it is only a matter of difference of opinion and taste, not resisting the revolution. In this case it is everyone's duty not to foment discrepancies," he said.   

Khamenei made a rare intervention in April to stop Ahmadinejad sacking Intelligence Minister Heydar Moslehi. The attempted sacking was seen by Ahmadinejad's critics as a political manoeuvre before next year's parliamentary elections, when the Intelligence Ministry will be in charge of checking the backgrounds of potential candidates.   Since then some lawmakers have talked openly about a possible impeachment and the judiciary has arrested several people close to Ahmadinejad's advisers in the so-called "deviant current.”