Iranian president Mahmoud Ahmadinejad is to fight a decision by election overseers to disqualify his top aide from the upcoming presidential race.
He called it an act of "oppression" and he will take the case to the country's supreme leader Ayatollah Ali Khamenei.
His comments camea day after the Guardian Council removed Esfandiar Rahim Mashaei from the final candidate list.
The ruling deals a serious blow to Mr Ahmadinejad's hopes of having a loyalist succeed him. He cannot run in the June 14 ballot because of the number of times he has already held office.
The council also barred ex-president Akbar Hashemi Rafsanjani, a centrist who revitalised reformist hopes. It approved eight hopefuls, mostly hard-line candidates associated with the clerical establishment.
Mr Ahmadinejad had clerical conservative backing until he was perceived to challenge Mr Khamenei's authority in 2011.