He joined 455 other hopefuls registering to contest the election due on June 14, ranging from Saeed Jalili, Iran’s chief negotiator on the nuclear issue, and Esfandiar Rahim Mashaei, the president’s chief of staff whose religious views have been denounced as “deviancy” and “heresy”.
Mr Rafsanjani’s surprise nomination could have the most impact. Once a pillar of the Islamic regime, he endorsed the opposition Green Movement during the last election in 2009, when Mahmoud Ahmadinejad, the outgoing president, won a bitterly disputed contest.
Mr Rafsanjani was then singled out for attack by the regime: his daughter, Faezeh, was jailed last year for spreading “propaganda against the ruling system”. She was released in March after spending 14 months in Evin prison.
Because of his loathing for Mr Ahmadinejad and his backing for the Green Movement, Mr Rafsanjani has won the support of some reformers. However, many question how he acquired his wealth and point out that he achieved little during his previous terms as president. Western diplomats see Mr Rafsanjani as a wily pragmatist, not a genuine reformer.
However, all the candidates have to be vetted by the Guardian Council, a powerful committee of senior clerics, before they will be allowed to run. This gives Ayatollah Ali Khamenei, the Supreme Leader, an opening to disqualify those of whom he disapproves.
Experts said he would face a difficult decision over whether to ensure that Mr Rafsanjani and Mr Mashaei are both vetoed. “The decision will depend on what guarantees more stability to the regime,” said Meir Javedanfar, an Iranian-born commentator at the Inter-Disciplinary Centre, an Israeli think tank.
“If the Revolutionary Guards and the intelligence ministry say they will damage stability, there’s no way they will be allowed to run. But if they can demonstrate real support and that barring them from taking part will hurt stability more, Khamenei will let them run. Whether they would then be allowed to win or not is another question.”
Mr Javedanfar added: “This is not going to be a real election – more a large primary in the Supreme Leader’s office.”
Insiders believe that Ayatollah Khamenei’s preferred candidates are Gholam Ali Hadad-Adel, a reliable former Speaker of parliament, who is related to the Supreme Leader by marriage, and Mr Jalili, an ideological hardliner who leads Iran’s negotiations with the West.
Another possible favoured candidate could be Mohammad Baqer Qalibaf, the mayor of Tehran who previously served as commander of the Revolutionary Guard air force. At one point, he was believed to be the Supreme Leader’s choice for the presidential election in 2005. But Ayatollah Khamenei changed his mind – amid speculation that he found Mr Qalibaf too moderate – and instead backed Mr Ahmadinejad.