Speaking at a meeting of reform-minded politicians on 8 February, Khatami said, “I will seriously take part as a candidate for the election.”

Supporters had pushed for Khatami to announce his candidature for months. He is widely regarded as the pro-reform politician most capable of beating Ahmadinejad.

“I never had doubts. Is it possible to remain indifferent toward the fate of the revolution and shy away from running in the elections?” Khatami said.

Ahmadinejad has yet to announce whether he will stand in the election, which will be held on 12 June.