Ahmadinejad's two main challengers in the June 12, 2009 election -- Mir Hossein Mousavi and Mehdi Karoubi -- who led months of mass protests against what they charged was massive fraud, have now been silenced.
Both men are under house arrest and are denied any contact with the outside world. Reformist former president Mohammad Khatami who for long championed their cause has gone to ground.
After a massive crackdown by the security forces which saw scores of protesters killed and hundreds of reformist activists and journalists sentenced to hefty jail terms, the few reformist newspapers that have survived have adopted a low profile.
But as the reformist challenge has waned, a simmering power struggle between Ahmadinejad and the dominant ultra-conservatives around supreme leader Ayatollah Ali Khamenei has burst out into the open.
In mid-April, the president took the audacious step of challenging a ruling from the supreme leader -- under the constitution in force since the Islamic revolution of 1979, the final arbiter on all matters.
Khamenei intervened when Ahmadinejad sacked Intelligence Minister Heydar Moslehi. He promptly reinstated the spy chief.
Ahmadinejad responded by withdrawing from public life for 10 days in a challenge to Khamenei's authority that infuriated the ultra-conservatives close to the supreme leader.
The president's critics charged that his attempt to replace Moslehi was linked to the intelligence minister's role in vetting election candidates.
Ahmadinejad is widely expected to field his own candidates against the ultra-conservatives who dominate the current parliament in elections due in March next year.
With little desire to deepen the rift in the conservative camp, Khamenei played down Ahmadinejad's antics, insisting he wanted the president to serve out his second and final term, which ends in in August 2014.
But he allowed his followers to lash out at Ahmadinejad's close entourage, including the president's chief of staff and closest confidant Esfandiar Rahim Mashaie, whom the ultra-conservatives accuse of being too liberal and nationalistic, and of wanting to undermine the Islamic regime.
Several of Ahmadinejad's staff have been arrested in recent weeks on various charges and one of his vice presidents has been found guilty of abuse of power.
Ultra-conservatives in the Shiite clergy and the elite Revolutionary Guard have repeatedly called for Mashaie's dismissal, accusing him of leading "a current of deviancy" and saying he has too much influence over the president.
Ahmadinejad has so far adamantly defended his aides, including Mashaie, but has attempted to defuse the pressure on his entourage with repeated public expressions of allegiance to Khamenei.
The president also triggered a showdown with the conservatives in parliament when he attempted to take personal charge of the oil ministry last month, in another move his critics linked to his ambitions for next year's elections.
The Guardians Council, the body which interprets the constitution, struck down Ahmadinejad's appointment of himself as caretaker of the key portfolio, ruling that it was the preserve of parliament to approve nominations.
The president finally backed down earlier this month and appointed a close ally as interim minister.
Khamenei has repeatedly called on his supporters to rein in their attacks on Ahmadinejad and his aides, most recently in a keynote address on June 4 marking the anniversary of the death of revolutionary leader Ayatollah Ruhollah Khomeini.
But the ultra-conservatives have yet to heed Khamenei's calls and continue to publicly criticise Ahmadinejad's entourage on an almost daily basis.
Last week, the president's key aide Mashaie even came in for a veiled attack from Ayatollah Mohammad Taqi Mesbah Yazdi, long considered to be the Ahmadinejad's spiritual mentor.
"The deviationists want to undermine the regime through money and propaganda, taking advantage of the credulity of the people... but this trash cannot do anything," the cleric was quoted as saying.