Tehran Mayor Mohammad Baqer Qalibaf has withdrawn from Iran’s presidential race to back hard-line cleric Ebrahim Raisi, leaving only one prominent conservative in the contest.
In a May 15 statement published by Iranian media, Qalibaf said the decision was vital for the "preservation of the interests of the people, the revolution, and the country."
Qalibaf called on his supporters to vote for Raisi on May 19, potentially strengthening the main conservative candidate challenging incumbent President Hassan Rohani.
"I ask all my supporters around the country to use all their capacity to help my brother Raisi win the election," Qalibaf said in his statement.
But some observers said Rohani could end up benefitting from the move.
"Not all of Qalibaf's voters will shift to Raisi, as the former represents the modernist current in the principlist [conservative] camp, while the latter represents the [hard-line] ideological factions," said International Crisis Group Iran analyst Ali Vaez.
Qalibaf, 56, had been running for president for the third time after being defeated in the 2005 and 2013 votes.
“We and the people expect that this decision will pave the way for a new era of economic development," he said.
Raisi praised Qalibaf’s decision as a "revolutionary move" in remarks at a campaign rally in the south-central city of Shiraz, where his supporters thanked Qalibaf for withdrawing from the race.
"Qalibaf, Thank you. Qalibaf, Thank you," Raisi’s supporters chanted, according to a video clip posted by the hard-line Fars news agency.
Vaez believes Qalibaf probably perceived his withdrawal as a win-win.
"It allows him to avoid an embarrassing third-time defeat in a presidential race, which according to the polls seemed likely, while scoring important points with the establishment in case his withdrawal helps Raisi," Vaez said in comments e-mailed to RFE/RL.
Vaez added that Raisi, who manages one of Iran’s wealthiest state charities, still faces an uphill battle, noting that the cleric lacks executive experience and charisma.
"His defeat would be a double-edged sword for his ambition to succeed the current supreme leader: The election would raise his profile and broaden his support-base, but it would be a setback -- albeit not a fatal one, as popularity is not the most determining factor for ascending to the pinnacle of power in the Islamic Republic," Vaez said.
Qalibaf has accused Rohani, a relative moderate, of mismanagement and of favoring rich Iranians at the expense of the poor.
Both Qalibaf and Raisi have said that Rohani has failed to translate the 2015 deal with global powers, which restricted Tehran's nuclear program in exchange for relief from economic sanctions, into a better life for Iranians.
Both have promised to create millions of jobs if elected and increase cash handouts to the poorer segments of the society.
Rohani has accused them of making unrealistic promises.
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In addition to Rohani and Raisi, Qalibaf's withdrawal leaves three other candidates in the race: Vice President Eshaq Jahangiri; who is seen as an ally of Rohani; centrist Mostafa Hashemitaba, who has said he will vote for Rohani; and conservative former Culture Minister Mostafa Mirsalim, who is far less prominent than Raisi.
In the past few days, the incumbent has received key endorsements from reformist former President Mohammad Khatami and opposition cleric Mehdi Karrubi, who has been under house arrest since 2011.
Khatami, who faces a media ban, issued a video on the Internet on May 14 urging Iranians to vote for Rohani.
"Mr. Rohani's government has been a successful one, despite all the limitations, problems, and the great expectations," Khatami said in the video.
"We should all go and vote for Rohani, for freedom in thought, logic in dialogue, law in action, securing the rights of citizens, and enforcing social and economic justice," Khatami added in the video, which was widely shared on social media.
"I urge the dear people of Iran to participate in the election and vote for their desired candidate in order to prevent inflicting more damage on the foundation of the republic," Karrubi was quoted as saying by the opposition Sahamnews website.
Karrubi was put under house arrest in February 2011 after challenging the Iranian establishment over the disputed 2009 vote and highlighting human rights abuses.
Opposition figure Mir Hossein Musavi and his wife, university professor Zahra Rahnavard, were placed under house arrest at the same time.
With reporting by RFE/RL Correspondent Golnaz Esfandiari, Fars, and ISNA