President Mahmoud Ahmadinejad showed rare defiance of his strongest backer, Iran's supreme leader, by insisting on his choice for vice president despite vehement opposition from hard-liners that has opened a deep rift in the conservative leadership. The tussle over the appointment comes at a time when the clerical leadership is facing its strongest challenge in decades following last month's disputed presidential election. Supreme Leader Ayatollah Ali Khamenei's top concern appears to be keeping the strong support of clerical hard-liners so he can withstand attempts by the more moderate opposition to erode his authority. Conservative clerics and politicians have denounced Ahmadinejad's choice for the post of first vice president, Esfandiar Rahim Mashai, because Mashai said last year that Iranians are friends with Israelis. There are also concerns because Mashai is a relative of Ahmadinejad – his daughter is married to the president's son. Khamenei ordered Ahmadinejad to remove Mashai, semiofficial media reported. Arguing for a further chance to make his case, Ahmadinejad said, “there is a need for time and another opportunity to fully explain my real feelings and assessment about Mr. Mashai.” The president may be digging in because he fears an attempt by hard-liners to dictate the government he is due to form next month. Iran has 12 vice presidents, and Mashai has been serving in one of the slots in charge of tourism and culture. Ahmadinejad said last week he was elevating Mashai to the first vice presidency. That is the most important of the 12 because it is in line to succeed the president if he dies, is incapacitated or removed. The first vice president also leads Cabinet meetings in the president's absence. Ahmadinejad is a member of the hard-line camp, but throughout his first term he had disputes over policy and appointments with fellow conservatives, some of whom accused him of hoarding too much power for close associates. Khamenei has been the president's top defender in the election dispute, dismissing opposition claims that Ahmadinejad's victory in the June 12 vote was fraudulent. Iran expert Suzanne Maloney pointed out that the supreme leader has not publicly spoken on the issue and reports of his order have been leaked by hard-liners through semiofficial media. “If Khamenei comes out in Friday prayers calling for (Mashai's) removal, then it would be difficult to imagine Ahmadinejad would refuse that,” said Maloney, with the Saban Center for Middle East Policy at the Washington