Incumbent President Hasan Fereidun Rouhani is favored to win re-election, and an Ahmadinejad candidacy would split the hardline vote, giving the advantage to President Rouhani.
Supreme Leader Ayatollah Khamenei appears to not have intervened so far to force them to do so. But responding to Ahmadinejad's desire for a political rebirth might require a more finessed response, analysts said.
Rouhani, who is considered politically moderate, has helped pull Iran out of sanctions imposed by the United Nations and the USA, though his critics say he has yet to deliver on many other domestic issues such as the growing unemployment rate.
"Rouhani is still very popular and he is in a very strong position".
The hard-liners have seized on popular discontent over the economy, and they tried to undermine and pressure Rouhani where they could.
For the time being, constant and green-friendly development, creating jobs and fighting social problems, say, poverty and addiction are among major concerns of his administration and he is determined to pace in this direction, Rouhani said. "It would be very unsafe to pin former President Ahmadinejad as being just a principlist... because there's a lot of the things that he has done within Iran in terms of internal policies that could qualify as being reformist".
Ahmadinejad, meanwhile, has been quietly trying to rebrand himself.
Ahmadinejad, who had a rift with Khamenei in his final years of office, announced in a public statement in October that he would abide by the order and would not run. "This was only an advice, not an order", Ahmadinejad told reporters. It is assumed he is running to offer an alternative for the moderates and reformists in case Rouhani is disqualified by the Guardian Council and said he stood "side-by-side" with the president. "Now we are through a long way from early years of the Revolution when we fought a battle nearly empty-handed with a regime well-equipped by hegemonic powers of the time; now, we hail the efforts of the army and defense industries for our current capabilities, where we have been manufacturing air fighter, armored carrier vehicle, helicopter and tanks, which indicates our self-sufficiency", he rejoiced to tell the meeting.
In their election calculations, hard-liners have been lining up behind Ibrahim Raeesi, a former judicial official.
U.S. Secretary of State John Kerry (L), U.S. Secretary of Energy Ernest Moniz (2nd L), Head of the Iranian Atomic Energy Organisation Ali Akbar Salehi (2nd R) and Iranian Foreign Minister Javad Zarif (R) wait with others ahead of a meeting at the Beau Rivage Palace Hotel in Lausanne on March 26, 2015. But his credentials are tainted by accusations that he was involved in a death committee that issued verdicts that led to the executions of thousands of political prisoners in 1988. But Ahmadinejad, at his news conference last week, suggested a three-way contest. These practices including not only the maintenance of the largest per-capita rate of executions in the world, but also internationally-outlawed execution of offenders who were below the age of majority, and the use of other forms of corporal punishment including flogging, amputations, and blinding. "However he has no choice but to play such a role", he said.
The registration for presidential elections officially started on April 11 and will end on April 15. He has held several sensitive jobs in the Islamic Republic, including representing Khamenei for 25 years at the Supreme National Security Council.
Ahmadinejad's candidacy may be a stunt to ensure at least one of his acolytes makes the cut.