Members of Iran's Revolutionary Guards march during a military parade to commemorate the 1980-1988 Iran-Iraq war in Tehran. Thomson Reuters BEIRUT (Reuters) — Iran's Revolutionary Guards look set to entrench their power and shift the country to more hardline, isolationist policies for years to come following the death of influential powerbroker Ali Akbar Hashemi Rafsanjani.

Former president Rafsanjani long had a contentious relationship with the Islamic Revolutionary Guard Corps (IRGC), which is both the strongest military force in Iran and also has vast economic interests worth billions of dollars.

With a presidential election in May and a question mark over the health of Iran's most powerful figure, Supreme Leader Ayatollah Ali Khamenei, analysts say the Guards will soon have opportunities to tighten their grip on the levers of power.

Rafsanjani, who died on Sunday aged 82, had criticized the Guards' expanding economic interests, which range from oil and gas to telecommunications and construction, their role in the crackdown on protests after disputed 2009 presidential elections and the country's missile program, which the Guards oversee.

Rafsanjani was a high-profile member of the Assembly of Experts that selects the Supreme Leader. Though he favored an easing of security restrictions on Iranians at home, opening up to the West politically and economically, he was a respected go-between who could balance the influence of hardliners.

Iran's Supreme Leader Ayatollah Ali Khamenei, right, Iranian President Hassan Rouhani, center, and former Iranian president Akbar Hashemi Rafsanjani attend Supreme Leader's meeting with authorities and ambassadors of Islamic countries, in Tehran. Thomson Reuters

During mourning ceremonies this week, senior Revolutionary Guards commanders appeared on state TV to praise Rafsanjani, a companion of the Islamic Republic's founder Ayatollah Ruhollah Khomeini and one of the pillars of the 1979 Islamic Revolution.

But analysts say many are quietly celebrating the departure of one of their biggest domestic critics.

"They're going to be very happy," said Ali Ansari, director of the Institute of Iranian Studies at the University of St Andrews. "They're shedding a lot of crocodile tears."

Absolutely pivotal

With Rafsanjani out of the picture the Guards can play a crucial role in determining who becomes the next Supreme Leader by steering Assembly members toward a candidate more sympathetic to their interests, analysts say.

Members of Iran's Basij militia march during a parade to commemorate the anniversary of the Iran-Iraq war (1980-88), in Tehran on September 22, 2010. Reuters

"All of the candidates you hear about who could replace Khamenei are much more hardline and have more radical views," said Mehdi Khalaji, a former seminarian from Qom who is a senior fellow at the Washington Institute for Near East Policy.

The hardline camp in Iran has defined itself by a deep distrust of Western governments and rigid opposition to internal political reform, whereas Rafsanjani was the leading force behind moderate President Hassan Rouhani's election win.

The 2015 nuclear agreement between Iran and Western powers was also anathema to hardliners and they have often used the deal, and the economic openings it offered Western companies, to criticize Rouhani's government.

The question of who could replace Khamenei, 77, was first raised in earnest when he was hospitalized in 2014.

In this photo released by the Islamic Republic News Agency (IRNA), members of the Iranian Revolutionary Guard celebrate after launching a missile in an undisclosed location in Iran, July 3, 2012. AP Photo/IRNA, Mostafa Qotbi

State TV showed Khamenei, who became the Islamic Republic's second Supreme Leader in 1989, in a hospital bed with a string of officials visiting. Analysts said this was done to help the public recognize that a change at the top was inevitable.

In the event of Khamenei's death, the Assembly of Experts' 88 members will hold a closed-door session to push for the candidate of their choice before a final vote is taken. Analysts expect the Revolutionary Guards to play a significant role.

"They'll be absolutely pivotal," said Ansari.

Pieces in place

The Revolutionary Guards first secured an economic foothold after the Iran-Iraq war of the 1980s when Iran's clerical rulers allowed them to invest in leading Iranian industries.

Revolutionary Guard Gen. Qassem Soleimani, center, attends a meeting with Supreme Leader Ayatollah Ali Khamenei and Revolutionary Guard commanders in Tehran, Iran, September 18, 2016. (Office of the Iranian Supreme Leader via AP)

Their economic influence, authority and wealth grew after former guardsman Mahmoud Ahmadinejad became president in 2005 and has increased since, leading some analysts to say the next Supreme Leader is unlikely to wield the same power as Khamenei.

"They have been putting all the pieces in place for a very forceful show of force if Khamenei passes away," said Abbas Milani, director of the Iranian Studies program at Stanford University.

"They're seizing every day one more lever of intelligence power, financial power, police power. Clearly they're putting their forces in play," Milani said.

While there is no clear single candidate for the role of Supreme Leader, there are a handful of top contenders.

One possible candidate is Ayatollah Mahmoud Hashemi Shahroudi, 68, a former head of the judiciary who is now deputy head of the Assembly of Experts.

Shahroudi is favored by Khamenei, experts say, and, crucially, is thought to have the backing of the Revolutionary Guards.

Iran's Judiciary Chief Ayatollah Sadegh Larijani speaks during a ceremony to mark Parliament day in Tehran, December 1, 2009. REUTERS/Morteza Nikoubazl

Another candidate is Ayatollah Sadeq Amoli Larijani, the 55-year-old current head of the judiciary who has twice been appointed to the position by Khamenei.

Larijani comes from a family of political heavyweights — one brother, Ali, is parliament speaker and another has served in government — but Sadeq is not regarded as a senior cleric and is unlikely to muster much support among the old guard.

A third possible candidate is Mohammad-Taqi Mesbah-Yazdi, a hardline stalwart who has tussled with reformists for years.

Mesbah-Yazdi did not get enough votes to keep his seat in the Assembly last year and, at 82, his age will likely be an issue if he is being considered for the top position in the country.

Some analysts say, however, that given the increasing power of the Revolutionary Guards it is perhaps less significant who actually becomes the next Supreme Leader.

"The individual is no longer important," said Khalaji at the Washington Institute. "When I get asked who's going to replace Khamenei, I say it's the Revolutionary Guards."

(By Babak Dehghanpisheh; editing by David Clarke)