The fiercely disputed re-election of President Ahmadinejad — a rival he despises — has forced Ali Akbar Hashemi Rafsanjani, a former two-time President, into an unlikely opposition role.

He is now the most powerful supporter of Mir Hossein Mousavi, the man that millions of Iranians believe was the real winner of last month’s elections.

Hojatoleslam Rafsanjani, 75, bolstered the embattled opposition with a surprisingly defiant sermon yesterday that implicitly criticised the Supreme Leader, Ayatollah Ali Khamenei, who has endorsed Mr Ahmadinejad’s “divine” re-election. For Hojatoleslam Rafsanjani to take sides so openly was uncharacteristic: he is a wily and cautious operator who has long kept a foot in Iran’s reformist and conservative camps, mostly manoeuvring behind the scenes as a potential kingmaker.

But he is concerned about his own political survival as well as the destiny of the Islamic Republic that he helped to found. He fears his legacy is being endangered by the firebrand President and the election that has lost the Islamic system any semblance of popular legitimacy.

Potentially, Hojatoleslam Rafsanjani holds a trump card: he chairs Iran’s top clerical body, the Assembly of Experts, which is empowered to elect, supervise and, in theory at least, to dismiss supreme leaders.

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