That dynamic seems to be playing out in the aftermath of the nuclear deal, with the supreme leader coming down hard on anything or anyone seeming to promote greater freedoms, as the latest dispute underlines.

On Sunday, an ally of the president, Hossein Marashi, a reformist leader, said that out of 3,000 reformist candidates who had registered nationwide, only 33 had been allowed to participate. While there is a 20-day appeal period, few analysts think the Guardian Council, which vets candidates for all elections and is dominated by hard-liners, would radically alter its decisions.

In the Tehran metropolitan area, Iran’s most populous, only four reformists out of 760 candidates were pronounced qualified to run, one newspaper affiliated with that faction, Arman-e Emrouz, wrote on Monday.

Hard-liners said the reformists were trying to make the council look bad by registering thousands of candidates they knew lacked the credentials to qualify. “Their plan is now to undermine the legality of the Guardian Council,” said Hamidreza Taraghi, a political analyst close to the hard-line camp. “But even so-called hard-liners have been disqualified. These people just want to create tension.”

But reformists argued that the council, like other hard-line factions, was overly sensitive to hints of liberalizing and eager to crack down on anybody who was at all critical of how the country was run. “With or without the nuclear deal, all of them would be disqualified,” said Farshad Ghorbanpour, an analyst with close ties to Mr. Rouhani. “They simply can’t stand criticism.”