First, the reports are coming from an unconfirmed second-hand source. This examiner.com article makes the claim:
A few minutes ago on May 5, 2011, Arab TV announced that Supreme Leader Ayatollah Khameini requested Iran’s President Ahmadinejad to step down from his post. This has not been confirmed nor verified by Western media as yet, however, it has been reported that several of his close aides are already under arrest.
Arab news outlets are reporting this as a disagreement over the firing of Heider Moslehi, the intelligence minister. Ahmadinejad fired the minister and Ayatollah Khamenei gave the intelligence chief his job back. Ahmadinejad felt this was meddling into the duties of his presidency and threatened to quit.
In recent days, President Ahmadinejad has been reported to be skipping cabinet meetings and otherwise shirking his duty. The expectation is that he will be forced to resign.
*update- Guarduan.uk is now reporting that Ahmadinejad has been told to take a cabinet position or resign.
An unprecedented power struggle at the heart of the Iranian regime has intensified after it emerged that the supreme leader, Ali Khamenei, had given an ultimatum to President Mahmoud Ahmadinejad to accept his intervention in a cabinet appointment or resign.
There is no hint of who might succeed Ahmadinejad as President or if the Ayatollah will remove the position and take direct control of the government. Either way, this could be a further destabilizing factor in a country that may well have been on the forefront of the current round of Mid-east countries in turmoil. The Ayatollah removing the President and keeping power for himself could set off another round of riots and a weaker replacement could embolden revolutionary elements.
*update – May 8, 2011- according to the Washington Post, “Apparently bowing to unprecedented pressure from Iran’s clerical establishment, President Mahmoud Ahmadinejad welcomed an intelligence minister he had ousted in April back into his cabinet meeting on Sunday.”
All appearances show that Ahmadenijad realizes he over-stepped his authority and is attempting to get back in the graces of Iran’s religious leadership.