Iran President Hassan Rouhani, left, with Pope Francis at the Vatican on Tuesday. (Pool photo by Andrew Medichini/via Reuters)

Iran’s election overseers have cleared only one-fifth of the potential candidates seeking a spot on the panel with powers to select the country’s next supreme leader, an official said Tuesday.

The rejections appear to be another stand by hard-liners seeking to hold back more moderate-leaning groups after some high-profile strides under President Hassan Rouhani, including a nuclear deal with world powers that lifted international sanctions.

Such widespread vetting of candidates is a fixture of Iranian politics that allows the culling of those perceived as potential threats to the ruling system and its protectors, led by the Revolutionary Guard Corps.

But next month’s twin elections — for the 290-seat parliament and the 88-member body known as the Assembly of Experts — are seen as important tests of whether more- conservative forces can maintain their voice in Iranian affairs.

Of the 801 candidates seeking to run in the election for the Assembly of Experts — a group with the powerful mandate to select Iran’s top leader — just 166 were approved for the Feb. 26 ballot, the state-run IRNA news agency reported, citing assembly spokesman Siamak Rahpeik. The assembly would name a successor after the death of the supreme leader, Ayatollah Ali Khamenei, who is 76.

Last week, Iranian media reported that the election gatekeepers, known as the Guardian Council, disqualified more than 7,000 of the 12,000 people seeking seats in parliament. Full candidate lists will be officially published closer to the election. Those disqualified have the option to appeal.

Many of the rejections are believed to be backers of Rouhani, who is on his first official trip to Europe, with meetings heavily concentrated on seeking renewed investment in Iran with sanctions now eased. Before the international sanctions, countries such as France and Germany were among Iran’s top trading partners.

Rouhani met Tuesday with Pope Francis at the Vatican.

The upcoming elections also show the dueling pressures faced by Khamenei. He gave a green light for Rouhani’s government to negotiate the deal with the United States and other world powers to limit Iran’s nuclear capabilities in exchange for the lifting of international economic sanctions. The pact angered some hard-liners who complained that it surrendered too much to the West.

But Khamenei has tried to ease their worries by calling for strict vetting by the 12-member Guardian Council, which is led by arch-conservative Ahmad Jannati, who has wider opinion-shaping powers as one of the leaders of the nationally broadcast Friday prayers at Tehran University.

Among those apparently opposed by the council was Hassan Khomeini, the grandson of Ayatollah Ruhollah Khomeini, the leader of Iran’s Islamic revolution. Hassan Khomeini, seen as a relative moderate, apparently withdrew his bid for the Assembly of Experts after getting signals that he faced likely disqualification.

Other members of the revolution leader’s family have openly challenged the ruling establishment in the past, including siding with reformist presidential candidates Mir Hossein Mousavi and Mehdi Karroubi — who led massive protests after the disputed 2009 election victory of Mahmoud Ahmadinejad. Mousavi and Karroubi later faced house arrest.

In 2013, the Guardian Council’s rejections for the presidential race included a former president, Ali Akbar Hashemi Rafsanjani. He retains leadership of the Expediency Council, which mediates possible disputes between parliament and the ruling clerics.

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