The Iranian president, Mahmoud Ahmadinejad, says he will challenge a ban preventing his political ally from standing in next month's presidential election.
Mr Ahmadinejad says he will petition Iran's Supreme Leader, Ayatollah Ali Khamenei, about the ban on Esfandiar Rahim Mashaei.
Mr Mashaei and ex-president Akbar Hashemi Rafsanjani have been excluded by the Guardian Council, which vets election candidates.
The eight men cleared to stand are all considered conservatives, the BBC reports.
The Guardian Council is loyal to Supreme Leader Ayatollah Ali Khamenei.
Mr Mashaei is a protege of Mr Ahmadinejad, who is barred under the constitution from seeking re-election on 14 June because he has served two consecutive terms in office.
Known for his controversial religious views, Mr Mashaei has been denounced by hardline clerics as part of a "deviant current" that seeks to undermine Iran's Islamic system.
