By Marcus George

DUBAI, May 11 (Reuters) - President Mahmoud Ahmadinejad's nationalist protégé Esfandiar Rahim Mashaie is one of the most divisive men in Iran, and if he is allowed to stand in June's presidential election, it would be a direct challenge to the authority of the supreme leader.

Mashaie brought to an end years of speculation on Saturday by registering as a candidate in an election that Supreme Leader Ayatollah Ali Khamenei hopes will usher in a period of much needed calm and unity.

But Mashaie's candidacy has the potential to tear apart the already strained political divisions between non-clerical populists, like him and Ahmadinejad, and loyal lieutenants of the Islamic theocracy, just four years after Iran was rocked by widespread protests over Ahmadinejad disputed re-election.

"Unlike the first generation of revolutionary elite who played by the rules, the Ahmadinejad group has consistently pushed against regime red lines and at times even challenged the authority of the supreme leader," said U.S.-based expert on Iran's electoral system, Yasmin Alem.

"For them, ambition trumps allegiance to the regime's principles."

Khamenei is supposed to be above the fray of every day politics, but personally intervened in 2009 to stop Ahmadinejad making Mashaie his first vice president.

Ahmadinejad was not completely cowed though and instead made Mashaie his chief-of-staff. For Mashaie to now run for president after Khamenei has shown his disapproval is an affront to the leader's authority, a cornerstone of the Islamic Republic.

"Allowing Mashaie to run for office would undermine the credibility of Iran's supreme leader," Alem said. "I think both Ahmadinejad and Mashaie are sly enough to know this."

The Ahmadinejad camp has also tested the nerves of "principlists" - those who profess total loyalty to the supreme leader - with their slogan of "long live Spring", which many have read as a coded call for political change.

But like all candidates, Mashaie first has to get through the vetting process by the Guardian Council - a group of 12 clerics and jurists responsible for overseeing the election.

"If Mashaie is barred, it might prompt Ahmadinejad to take action that would be destabilising," said Mohammad Shabani, an Iranian analyst based in London. "Regardless of whether Mashaie is approved as a candidate, his candidacy is bound to be fateful."

While loyalists lose sleep over a possible Mashaie presidency, others are not sure the 52-year-old can win.

"I don't see a Mashaie presidency at this stage," said a Western diplomat based in Tehran. "He's a dark horse but my best guess is he'll be barred from contention."


CLERICAL WRATH

Mashaie grew up inside the murky politics of the Islamic Republic, joining the intelligence ministry in the 1980s and serving in Iran's Kurdistan province where he met Ahmadinejad.

He rose to prominence when Ahmadinejad, at that point a little-known mayor of Tehran, astonished the Iranian nation by winning the presidency in 2005. They came even closer when Mashaie's daughter married Ahmadinejad's son in 2008.

A background figure in the cabinet, Mashaie shot to notoriety in Iran the same year when he said Iran was a friend of the people in the United States and Israel, which incurred the wrath of hardline clerics and politicians alike.

Since the Islamic Revolution, Iran has held a deeply hostile stance against what it calls "the Zionist regime" and has levied considerable support and encouragement for Palestinian groups.

But perhaps Mashaie's greatest sin in the eyes of the conservative establishment was to involve himself in religious debate, traditionally the preserve of clerics in Shi'ite Islam.

"Without Iran, Islam would be lost," Mehr news agency quoted him as saying in 2010. "Countries are scared of Iran, because the truth of Islam is here."

Comments like those and others indicate Mashaie is seeking "a reorientation of Iranian state identity", Shabani said. "One way of doing this is to seek to end the clerical monopoly on promulgation of the nature of Iran's Islamic identity."

Clerics have also blasted Mashaie and Ahmadinejad for making "seditious and erroneous" comments about the Mahdi, the holy saint who Shi'ite Muslims believe will return to re-establish the rightful governance of Islam.

Regardless of the pressure, the president has stood by him.


NATIONALISTIC AND MESSIANIC

"Ahmadinejad's unconditional devotion to Mashaie is no secret," Alem said. "While neither man has shied away from letting their unbreakable bond become public, the exact nature of their relationship is suffused in mystery.

"His political outlook is an amalgam of nationalistic and Messianic beliefs," she said.

For the past eight years, Ahmadinejad and Mashaie, who was previously head of Iran's cultural heritage organisation, have fine-tuned a strongly nationalist doctrine that analysts say is increasingly popular among young and secular groups and those tired of their leaders' incessant Islamic rhetoric.

Iranians are deeply proud of their pre-Islamic traditions and heritage and the two have strived to harness such symbols.

Perhaps the most blatant example of the new doctrine was the loan by the British Museum to Tehran of the Cyrus Cylinder - a pre-Islamic, 2,600 year old clay antiquity that scholars regard as the "first bill of human rights".

"That was the one thing they wanted to borrow," said British Museum director Neil Macgregor in an interview with CNN.

Ahmadinejad attended the cylinder's Tehran unveiling in 2010, a move that would have been inconceivable for previous presidents. But Mashaie's central role in the affair stands out.

"Mr Mashaie began talking about Cyrus as a forerunner of the prophet (Mohammad), as also embodying values that can be part of an Islamic tradition," Macgregor said in the interview.

Linking the prophet with a pre-Islamic imperialist Persian monarch does nothing but stoke further fears among the Islamic Republic's old guard about Mashaie's intentions. (Editing by Jon Hemming)

Earlier on HuffPost:

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  • Ali Akbar Velayati

    Top adviser to Supreme Leader Ayatollah Ali Khamenei on international affairs. Velayati, 67, Served as foreign minister during the 1980-88 war with Iraq and into the 1990s. He is a physician and runs a hospital in north Tehran. He was among the suspects named by Argentina in a 1994 bombing of a Jewish center in Buenos Aires that killed 85 people. <em>Caption: Ali Akbar Velayati, adviser to Iran's supreme leader Ayatollah Ali Khamenei, speaks during a press conference at the Iranian Embassy in Damascus on August 9, 2010. (LOUAI BESHARA/AFP/Getty Images)</em>

  • Mohammed Baqr Qalibaf

    Tehran mayor and former commander of the Revolutionary Guard during the Iran-Iraq war. Qalibaf, 51, is a pilot who enjoys good relations with Khamenei. <em>Caption: Tehran Mayor and expected future presidential candidate, Mohammed Baqr Qalibaf, stands in front of an Iranian flag, during a tree planting ceremony in 'Dialogue Park' March 6, 2007 in Tehran, Iran. Qalibaf, a former national chief of police and revolutionary guard soldier, was defeated in the June 2005 presidential poll when he ran a 'modern' conservative campaign. He is seen as a strong contender in the 2009 election for president. (Scott Peterson/Getty Images)</em>

  • Hasan Rowhani

    A former nuclear negotiator and Khamenei's representative at the Supreme National Security Council, which also handles the nuclear dossier. Rowhani, 64, is a British-educated cleric. <em>Caption: Iran's top nuclear negotiator, Hasan Rowhani, who chairs the Iranian Supreme National Security Council, speaks with media during a press conference March 13, 2004 in Tehran, Iran. Iran imposed an indefinite freeze March 13 on international inspections of its nuclear facilities to protest a critical resolution passed by the International Atomic Energy Agency. (Photo by Majid/Getty Images) </em>

  • Mohammad Ali Aref

    Liberal-leaning former vice president under reformist President Mohammad Khatami. Aref, 62, a former Tehran University chancellor, said he would drop out of race if Khatami decides to run. <em>Caption: Iran's oil minister Bijan Namdar-Zanganeh (L) and Iran's first vice president, Mohammad Reza Aref (R) visit the Balal offshore oil platform in the Gulf waters, in the Gulf on the edge of Qatar's territorial waters, 16 May 2004. (BEHROUZ MEHRI/AFP/Getty Images)</em>

  • Esfandyar Rahim Mashaie

    A top adviser to President Mahmoud Ahmadinejad and married to Ahmadinejad's daughter. His candidacy is being heavily promoted by Ahmadinejad, but he will face serious hurdles during the vetting by the Guardian Council, which must approve all candidates. Mashaei, 52, was denounced as leader of a "deviant current" during Ahmadinejad's political showdowns with Khamenei. <em>Caption: Head of the Iran's presidential office, Esfandyar Rahim Mashaie, reads from the Persian translated copy of 'The Audacity of Hope' by Barack Obama, during his interview with AFP in Tehran on October 11, 2009. (BEHROUZ MEHRI/AFP/Getty Images)</em>

  • Mohsen Rezaei

    Former chief commander of the Revolutionary Guard. Rezaei, 58, ran in 2009, but finished fourth. He is currently secretary of the Expediency Council, which mediates between the parliament and Guardian Council. <em>Caption: In this photo taken on Sunday, May 3, 2009, Iranian presidential hopeful Mohsen Rezaei, a former Revolutionary Guards chief, sits prior to his press conference in Tehran, Iran. For eight years, Iran’'s President Mahmoud Ahmadinejad has played the role of global provocateur-in-chief: questioning the Holocaust, saying Israel should be erased from the map and painting U.N resolutions as worthless. Now, a race is beginning to choose his successor -- candidate registration starts Tuesday for a June 14 vote -- and it looks like an anti-Ahmadinejad referendum is shaping up. (AP Photo/Vahid Salemi)</em>