By Parisa Hafezi
ANKARA (Reuters) - President Hassan Rouhani, who registered on Friday to seek a second four-year mandate in a May 19 election, helped end Iran's diplomatic and economic isolation in his first term by clinching a landmark nuclear deal with major powers.
But, despite remaining faithful to Iran's theocratic system, Rouhani has angered hardliners with his calls for improved relations with the West, more freedom of expression and an easing of strict Islamic rules.
"Once again, I am here for Iran, for Islam, for freedom and for more stability in this country," Rouhani told reporters on Friday when announcing his bid.
Rouhani's hardline critics accuse him of having encouraged moral corruption in society by advocating social tolerance. Some erstwhile supporters who had hoped for radical social changes under his presidency are also critical, saying he has failed to stand up to Iran's conservative religious establishment.
"Rouhani is a regime insider. He is loyal to the establishment. He is not a reformist but a bridge between hardliners and reformists," said a former senior official.
"He lacks enough power to confront those who are against reforms, whether social or economic."
The president's constitutional powers are limited. Ultimate authority rests with Supreme Leader Ayatollah Ali Khamenei, who has accused the West of using women as a tool to advertise products and satisfy "disorderly and unlawful sexual needs".
Some analysts doubt that Rouhani, who was elected in a landslide in 2013 on a pledge to reduce Iran's isolation and create a freer society, has enough will to improve the country's human rights situation.
Others believe Rouhani has depleted his political capital with the Supreme Leader by securing his consent to the 2015 nuclear deal, leaving nothing for domestic reforms.
Born into a religious family in 1948, the mid-ranking Shi'ite cleric played an active role in the opposition that overthrew the U.S.-backed Shah in 1979. He has held several sensitive jobs in the Islamic Republic, including representing Khamenei for 25 years at the Supreme National Security Council.
Rouhani is also a member of the Expediency Council and the Assembly of Experts, two influential advisory bodies in Iran's multi-tiered power structure. The latter will choose the country's next supreme leader.
Human rights campaigners say there have been few, if any, moves to bring about greater social freedoms as Rouhani's main focus has been boosting the sanctions-damaged economy.
Khamenei and his hardline allies have strongly criticised the slow pace of economic revival since the lifting of sanctions last year, part of the nuclear deal with six major powers whereby Tehran agreed to curb its nuclear programme.
Many remaining unilateral U.S. sanctions, have hindered the foreign investment that could fuel an economic recovery.
Strong criticism of Rouhani's economic record by hardliners including Khamenei in recent weeks have led some analysts to speculate whether the president may still be blocked from seeking another term.
The hardline Guardian Council, which vets candidates before they stand, has prevented other influential figures from running in previous elections.
But insiders said disqualifying a sitting president might be very costly for the establishment, especially given a hostile U.S. administration in Washington. President Donald Trump has frequently criticised the nuclear deal with Iran.
"With the deal in jeopardy, the system will be in vital need of Rouhani’s team of smiling diplomats and economic technocrats to shift the blame to the U.S. and keep Iran's economy afloat," said Iran analyst Ali Vaez of the International Crisis Group.
Influential Shi'ite cleric Ebrahim Raisi, the custodian of a powerful organisation in charge of Iran’s holiest shrine, appears to be the leading hardline candidate in the presidential race, though some prominent conservatives have already thrown their weight behind Rouhani.
Political analysts said they expected Iranian voters to rally around Rouhani even though many complain that they have still seen few economic benefits from the lifting of sanctions.
"Rouhani is still very popular and he is in a very strong position ... People will vote for him to prevent a hardliner from winning the election," said political analyst Saeed Leylaz.
(Editing by Gareth Jones)