With Iran’s field of presidential hopefuls now clear, the list of mostly conservative nominees begin their official campaigning Wednesday. (Vahid Salemi/AP)

Iran’s conservatives, who on Tuesday saw the two main moderate threats to their dominance barred from running in next month’s presidential election, face a new challenge: persuading shocked and skeptical Iranians to turn out to vote.

With the field of hopefuls clear, the mostly conservative nominees whose candidacies were approved by Iran’s Guardian Council officially launched their campaigns Wednesday, apparently free from the challenges of the most talked-about candidates, two-time former president Ali Akbar Hashemi Rafsanjani and the top aide to President Mahmoud Ahmadinejad, ­Esfandiar Rahim Mashaei.

Of the eight approved candidates, Iran’s lead nuclear negotiator, Saeed Jalili, who is a close adviser to the country’s supreme leader, appears to have mounting support among conservative politicians. But he cannot credibly claim popular backing, never having won an election, and his platform of “resistance” is unlikely to win votes from a populace eager for relief from the international economic sanctions imposed on Iran because of its nuclear activities.

Many Iranians seemed more interested in the fates of the two big names who were rejected than in those who were cleared to run, and it remained uncertain Wednesday how Iran’s leaders intend to try to revive the interest sparked by the surprise candidacies of Rafsanjani and Mashaei.

“I swear that every passenger who sat in this car in the past week said they would only vote for the old lion, Rafsanjani,” said a Tehran taxi driver who spoke on the condition of anonymity for fear of government reprisal. “I don’t think any of them will vote now.”

Who will be the next president of Iran? Here are the eight candidates running in the upcoming presidential election.

Ahmadinejad on Wednesday denounced the decision to disqualify Mashaei and suggested he would use his influence to have it reversed.

“I introduced Mashaei because I know him as pious and a fair manager,” Ahmadinejad said in comments posted on his Web site. “I will follow up the matter with the supreme leader until the last minute and hopefully it will get solved.”

Security in Tehran was elevated Wednesday, with riot police stationed at major squares, but there were no reports of unrest.

Iran’s volatile currency market also responded to Tuesday’s announcement with a drop in value of nearly 3 percent Wednesday morning, offering a glimpse of how the bazaar views the remaining candidates and their potential effect on the economy.

The brief candidacies of Rafsanjani and Mashaei, announced simultaneously on the final day of registration Saturday, had many parallels, but their forced exits from the race highlighted the differences in their ties to Iran’s power structure and hinted at the roles they may play in future.

Mohammad-Reza Sadeq, an adviser to Rafsanjani, said in a statement that the former president would “definitely announce his opinion of the Guardian Council’s decision, but his background shows that he always moves in the framework of law and national interest” — suggesting that Rafsanjani is unlikely to publicly challenge his disqualification.

Mashaei, with Ahmadinejad’s unwavering support, is less likely to quietly step aside, which could result in even greater hostility between their team and the conservative establishment.

His campaign issued a statement almost immediately after his disqualification, urging Ayatollah Ali Khamenei, the supreme leader, and Ahmadinejad to intervene to overturn the Guardian Council’s decision.

Cultivating interest in the June 14 vote now falls to Iran’s state media, with none of the candidates having a nationwide base of popular support. After their names were announced on state television Tuesday night, a pre-taped introduction to each was aired in which they briefly present their campaign pledges.

Besides Jalili, the three candidates seen as having the best chances are Ali Akbar Velayati, a former foreign minister and longtime adviser to Khamenei; Hassan Rouhani, a former lead nuclear negotiator; and Mohammad Bagher Ghalibaf, the mayor of Tehran.

Ghalibaf, an early favorite, suffered a blow last week when an audiotape surfaced in which he allegedly takes responsibility for violently suppressing protesters in 2003. His campaign team said the recording was doctored and released by his political adversaries. Despite the setback, Ghalibaf is considered the candidate with the most popular support, and he is the only one who has won a major election.

“My basic slogan is to solve economic problems and make a good life, materially and spiritually, for the people. The main point is to return hope, stability and peace to the society,” Ghalibaf said in his recorded message.

He and Jalili are expected to vie for the support of Iran’s conservative establishment. The two most moderate candidates left in the race, Rouhani and former first vice president Mohammad-Reza Aref, are not seen as posing a major threat. That could change, though, as former presidents Rafsanjani and Mohammad Khatami are expected to throw their support behind Rouhani.