Congratulations poured in for ultraconservative Ebrahim Raisi on Saturday on winning Iran's presidential election as his rivals conceded even before official results were announced.

The other three candidates in the race congratulated him for his victory, which had been widely expected after a host of heavyweight rivals had been barred from running.

“I congratulate the people on their choice,” said outgoing moderate President Hassan Rouhani without naming Raisi. “My official congratulations will come later, but we know who got enough votes in this election and who is elected today by the people.”

Meanwhile, Prime Minister Imran Khan also congratulated Raisi on his "landmark victory". "Look forward to working with him for further strengthening of our fraternal ties and for regional peace, progress and prosperity," he said on Twitter.

The other two ultraconservative candidates — Mohsen Rezai and Amirhossein Qazizadeh Hashemi — explicitly congratulated Raisi, as did the only reformist in the race, former central bank governor Abdolnasser Hemmati.

Raisi, 60, takes over from Rouhani in August as Iran seeks to salvage its tattered nuclear deal with major powers and free itself from punishing US sanctions that have driven a sharp economic downturn.

Raisi, the head of the judiciary whose black turban signifies direct descent from Prophet Muhammad (PBUH), is seen as close to the 81-year-old supreme leader, Ayatollah Ali Khamenei, who has ultimate political power in Iran.

Friday's voting was extended by two hours past the original midnight deadline amid fears of a low turnout of 50 per cent or less.

The ballots were counted overnight and authorities were yet to release the official result or turnout figures.

Many voters chose to stay away after the field of some 600 hopefuls, including 40 women, had been winnowed down to seven candidates, all men, excluding an ex-president and a former parliament speaker.

Three of the vetted candidates dropped out of the race two days before Friday's election and two of them quickly threw their support behind Raisi.

Populist former president Mahmoud Ahmadinejad, one of those who were barred from running by the Guardian Council of clerics and jurists, said he would not vote, declaring in a video message that “I do not want to have a part in this sin.”

'Save the people'

On election day, pictures of often flag-waving voters dominated state TV coverage, but away from the polling stations some voiced anger at what they saw as a stage-managed election aiming to cement ultraconservative control.

“Whether I vote or not, someone has already been elected,” scoffed Tehran shopkeeper Saeed Zareie. “They organise the elections for the media.”

Enthusiasm was dampened further by spiralling inflation and job losses and the pandemic that proved more deadly in Iran than anywhere else in the region, killing more than 80,000 people by the official count.

Among those who queued to vote at schools, mosques and community centres, many said they supported Raisi, who has promised to fight corruption, help the poor and build millions of flats for low-income families.

A nurse named Sahebiyan said she backed him for his anti-graft credentials and on hopes he would “move the country forward [...] and save the people from economic, cultural and social deprivation”.

Raisi, who holds deeply conservative views on many social issues including the role of women in public life, has been named in Iranian media as a possible successor to Khamenei.

To opposition and human rights groups, his name is linked to the mass execution of political prisoners in 1988. The US government has sanctioned him over the purge, in which Raisi has denied playing a part.

'Maximum pressure'

Ultimate power in Iran, since its 1979 revolution toppled the US-backed monarchy, rests with the supreme leader, but the president wields major influence in areas from industrial policy to foreign affairs.

Rouhani, 72, leaves office in August after serving the maximum two consecutive four-year terms allowed under the constitution.

His landmark achievement was the 2015 deal with world powers under which Iran agreed to limit its nuclear programme in return for sanctions relief.

But high hopes for greater prosperity were crushed in 2018 when then US president Donald Trump withdrew from the accord and launched a “maximum pressure” campaign against Iran.

While Iran has always denied seeking a nuclear weapon, Trump charged it was still planning to build the bomb and destabilising the Middle East through proxy groups in Iraq, Lebanon, Syria and Yemen.

As old and new US sanctions hit Iran, trade dried up and foreign companies bolted. The economy nosedived and spiralling prices fuelled repeated bouts of social unrest which were put down by security forces.

Iran's ultraconservative camp — which deeply distrusts the US, labelled the “Great Satan” or the “Global Arrogance” in the Islamic republic — attacked Rouhani over the failing deal.

Despite this, there is broad agreement among Iran's senior political figures, including Raisi, that the country must seek an end to the US sanctions in ongoing talks in Vienna aimed at rescuing the nuclear accord.