They stood in separate lines to vote under the great turquoise dome of the Hosseinieh Ershad Mosque in northern Tehran yesterday morning, one in the men’s queue, the other with the women.

Both were preparing to cast their ballots for Mir Hossein Mousavi. Three decades after they parted company over the occupation of the US Embassy in the wild months that followed the rebellion against the Shah, it was a sort of spiritual and political reunion.

Back then, Masomeh Ebtekar was a teenage revolutionary. Having lived in America, she spoke perfect English and became the spokeswoman for the Islamic students who stormed the embassy. They held 52 diplomats hostage for 444 days and helped to bring about the defeat of President Carter in the 1980 US presidential election after helicopters sent to rescue the hostages crashed in the desert.

Day after day she would appear, proud and defiant, on Western television and in the newspapers of Europe and America, denouncing American “crimes” and labelling the diplomats as “spies”. She earned the ironic nickname Sister Mary, because she vaguely resembled a nun in her black headscarf and chador. Much later, she became Iran’s first female vice-president under the reformist presidency of Mohammed Khatami.

Ebrahim Yazdi was a leader of the Freedom Movement, a group that opposed the Shah. After the revolution he became the first Foreign Minister of the new Islamic Republic. He did not hold the job for long, but resigned in protest after the students stormed the embassy.

Yesterday, older and greyer, both returned to the mosque that had once been a nerve centre of pre-revolutionary opposition to the Shah. Both backed Mr Mousavi, a relative moderate, against the fiery fundamentalist Mahmoud Ahmadinejad, whose presidency has once again made Iran a pariah in the eyes of the world.

The election was a referendum on Mr Ahmadinejad because he had failed to deliver on his promises, Dr Ebtekar told The Times. He had presided over four years of economic decline, rising inflation and high unemployment and he could have dealt more rationally with the rest of the world without compromising Iran’s dignity and independence.

“People see that in many, many areas, the country has turned back and not advanced,” she said. “There is a lot of enthusiasm for change in the country.” Mr Mousavi would improve the economy and restore civil rights and freedoms, she said.

Mr Yazdi, 78, was even more scathing about Mr Ahmadinejad’s performance. In foreign affairs it had been “destructive — and a by-product of destruction is disaster”.

He said that Mr Mousavi was well aware of Iran’s isolation in the world and there was now a “consensus at the top level of decision-making in Iran to reconcile with the West, and particularly with America”. He believed that a compromise to resolve the confrontation over Iran’s nuclear programme was possible.

First, however, Mr Mousavi must win the election. Mr Yazdi said he expected that there would be attempts to rig the ballot in Mr Ahmadinejad’s favour — and if that happened there could well be violent protests. “Our youth can’t tolerate that kind of behaviour,” he said. As they did in 1980, Iranian students might once again take matters into their own hands.

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