One of two reformists approved to run in this week's Iranian presidential election, Mohsen Mehralizadeh, on Wednesday withdrew his candidacy, Iranian media reported.
That leaves six hopefuls in the race for Friday's election, widely expected to be won by ultraconservative judiciary chief Ebrahim Raisi.
Former vice president Mehralizadeh, 64, was one of only two reformists permitted to run in the election to replace President Hassan Rouhani, who has served the maximum two consecutive terms.
Mehralizadeh's withdrawal was first reported by the state IRNA news agency, which did not give a source, and then by its counterpart ISNA, which quoted a spokesman for his campaign.
The spokesman gave no explanation but said an official statement would be issued "in a few hours", ISNA said.
Mehralizadeh was trailing in pre-election opinion polls, the only candidate to score less than one percent of voter intentions, according to the ISPA polling institute.
His departure leaves just one candidate in the race who is considered a reformist, former central bank chief Abdolnasser Hemmati, 66, AFP reported.
But the clear front-runner is Raisi, seen as close to the supreme leader, Ali Khamenei, after the disqualification of several political figures who presented a significant challenge to him at the ballot box.
According to the few polls available, voter abstention could exceed the record of 57 percent recorded in parliamentary elections last year.
