A brave people went in their millions yesterday to vote for the next president of Iran.

They went for the right reasons and they went for the wrong reasons but they wanted a say in how their country is governed. In their tens of thousands, they waited in Tehran amid the sword-like heat of summer to insist that they had duties and obligations towards their society. Alas, the clerical blanket which smothers Iran will ensure that mullahs - not people - ultimately get their way. Thank you, Ayatollah Khomeini.

Not since the first free Iraqi elections have a Middle Eastern people so staunchly demonstrated their right to be heard. The last elections in Iran provided a 60 per cent turnout. Now some were saying it was 80 per cent, even 85 per cent. I found the mosques and schools of Tehran packed to capacity, the overflow winding back down the hot pavements and across the baking highways.

Never before in Iran - not since the Islamic Revolution that brought all this about - have I heard such a thunder of free speech. No, it is not a new Iran we are going to see, even if the favourite Mirhossein Mousavi wins the ticket. (Both Mousavi and the unbalanced Mahmoud Ahmadinejad were last night claiming victory.) But it will be a little bit stronger than it was before. Please God, not a little bit more dangerous.

This new spirit could be heard outside the Issar School voting booths in Shaheed Mozaffarikhah Street - yes, of course this martyr died in the 1980-88 Iran-Iraq war, but then that awesome conflict had a lot to do with the turnout, as we shall see. "There are different reasons why I am here," Mariam Amina said to me, the less courageous voters - who didn't want to talk to the foreign journalist - listening to her every word. "I was not going to vote - I wasn't. But then I thought my silence would help someone who is not qualified to be president of Iran. And I thought my one vote would be worth it and that the person who becomes president would be a good president." Could there be a better reason for any democrat in the world to vote? The psychology student did suggest - unwisely, as I pointed out to her - that the British did not vote in such numbers "because they don't need to change their government". Corruption, I gently offered, is not a uniquely Arab or Iranian phenomenon - but her courage drew others to talk. A trickle of words turned into a waterfall. Ehsan, his unwillingness to give his family name told its own story - got the day about right. "Maybe people aren't here for the voting," he said. "Maybe it's only a political demonstration against the regime. We don't have any way to say why we need to change."

Minar - suffice it to say that every woman was scarved or chadored, albeit with ever increasing fringes of hair glistening beneath the sun - thought the "unpredictable debates" on Iranian television had a role in bringing the people of Tehran on to their canyon-like streets. "No one knew what would be said on television. That's why so many people are taking part in this election. The Supreme Leader [Ayatollah Khamenei] didn't want those cameras but they were there."

They were indeed, and there was much conversation among the crowd as to why the long-dead Ayatollah Khomeini had laid this permanent crust of Islamic rule over a real democracy of the people. Ehsan thought it accounted for the failure of the Mohamed Khatami government, "the chain over us," he called it. "There are people surrounding the Supreme Leader and they are all in line with him."

Then came the shadows that always lie away from the blinding sunlight of Tehran. A man called Kurosh - "Kurosh" is Persian for Cyrus, as in Cyrus the Great - took me to the shade on the other side of the street. He didn't want to be heard. "In the case of Mirhossein [Mousavi], he might have a successful vote, he could save the country freely. But I think in the next years, there may be a bloodbath in Tehran, because there are two totally divided sides in the country. All this is silent at the moment..."

Quite so. On Thursday, for the second time in five days, the judiciary authorities closed down the pro-Mousavi newspaper Yaseno. President Ahmadinejad's boys were at work again. And as I drove to the poverty of south Tehran - you always know you are heading for the poor here, because all roads to them lead downhill - there were those childish posters of the ever-smiling country boy who is still - just - the President. Ahmadinejad running in his sports clothes, Ahmadinejad among his smiling people, Ahmadinejad playing football.

Inside the Hasrat Rasoul Mosque - and here we were definitely amid the poverty of the capital - there were three state television cameras (Ahmadinejad's work again, of course) and there were thousands waiting to vote, old bearded men, young labourers, half shaved, in dirty trousers, and on the other side of the "masjid" a row of women, their chadors billowing in dark clouds. "For Ahmadinejad, naturally," came the first male voice. "Because he's an expert and an uncorrupt person. I didn't vote for him last time because I didn't know him. But his plans have always been complete and successful."

What was this? The man who has turned Iran into a laughing stock, who clearly cannot understand economics - reporters do sometimes have to tell the truth - is "complete" is he? He is "successful" is he? Though at the end, that's what his election result might prove to be. Then 52-year-old Hassan Danesh revealed himself. He runs a clothing store in the Great Tehran Bazaar. Same old story, the bazaaris in league with the clerics, just as they were in the 1979 revolution. Then a shock. A veteran of the 1980-88 Iran-Iraq war, white-haired now, Asghar Naderzadeh stepped towards me. He was a Basiji, a religiously inspired volunteer to fight Saddam, fought at Shalamcheh, arrived on the front lines at the age of just 14. "I want Mirhossein," he said. "The war veterans all know him as a good person. He managed the war perfectly and controlled inflation during this period." The old Basiji, it should be understood, were heroes and died for Iran. The new version, the young men who never fought but cluster around the Supreme Leader, are a political breed.

Another man, after Asghar, nameless this time but voting once more for Mirhossein "because of the way he speaks, his promises..." And then, inevitably, the voice of conservative womanhood. "All the time, Iran is a victory for Muslims. Everywhere imperialism has intimidated countries. We are all supporters of the Supreme Leader and the [Ahmadinejad] government." Untrue. Samaya was voting for the first time, a job in public relations management, who had listened to all four candidates in the televised debates. "It's my responsibility to vote for my president, Mirhossein Mousavi. His personality is fit for being a president."

We were all being watched and listened to - at far too close quarters - by a young army officer, a lieutenant with an AK-47 rifle, unshaven but with hard, strong eyes. Was this Big Brother, coming to betray those who wished to speak their minds?

Again, another woman, 27-year-old Marjan, a student of English translation at Tehran university, in jeans and a long black cloak and scarf. "I love my country and I love my revolution and I would like a good president for my country, Mr Mousavi. He helped save our country." It seemed the 1980-88 war cannot go away.

An older lady now. "We want to protect the blood of our martyrs in the war. I am the sister of a martyr who died in battle at Fakkeh in Khuzestan, a housewife with two daughters and I want Ahmadinejad." Then came the classic illogicality. "I don't want Mousavi to be president because he's going to promote bad 'hijab'. We don't need more freedom for girls to go out in bad dresses."

She was not alone. Kobra, a nurse in a scarf and purple coat, wanted the same as the housewife in front of her. "I vote because of my beliefs, because of love for this country's Islam and for the blood of our martyrs. It must be Ahmadinejad. He is the icon of resistance and courage." This was extraordinary. Kobra was transposing Ahmadinejad from hero of the 1980-88 war - which he was not - into hero of the war against George W Bush, a war of threats, to be sure, but certainly not a war of weapons. And then Kobra surprised us all. "I think President Obama is approaching Iran properly and this will be accepted in our society. We want other people in other countries to acknowledge us as human beings. All of us believe in God, like the Christians and the Jews. You believe in Jesus, we believe in Mohamed. We are all the same. In this election, I am looking for a channel to express my ideas. Tell everyone that we love Western countries."

This was a deeply moving statement of love and belief to come from an Ahmadinejad voter but just at that moment, the army lieutenant came up to me, rifle over his shoulder. "We are persuading these elements that we are having a democracy in Iran," he told me. "But democracy is for people who know their own intentions. Iranian people don't know what they want. Democracy will not work here. People should be educated, then they know what they want. Don't you believe that?" I said that you cannot filter out the poor from the educated and let only the rich and the powerful rule. I guessed the soldier was a bright man - I was right, he was a mining engineer in civilian life - but then up came the man from the interior ministry and the man from the governorate and told the soldier he was not allowed to talk to journalists. And this was when Lieutenant Zuheir Sadeqinejad of the Iranian army replied. "I was asking the journalist questions," he snapped back. "And I have the right to speak."

And I wondered if - despite his flawed argument - he wasn't the greatest democrat of them all.

The expats' view: 'I knew we had to come out'

With its patio cafés and millionaire mansions, Kensington Court in west London is usually more accustomed to the genteel comings and goings of its well-heeled residents. Yesterday it could have been mistaken for north Tehran. Thousands of chanting Iranians gathered outside the Iranian consulate to cast their vote - something that expats have rarely done during previous elections. But this year's presidential race has invigorated Britain's Iranians like never before thanks to the astonishing rallies of the reformist candidate Mirhossein Mousavi. Maryam Gol, who left Iran in 1974 and now lives with her family in Milton Keynes, was one of hundreds patiently queuing up to vote yesterday afternoon. It was the first time she had cast a ballot since settling in the UK. "When I saw just how many young people came out to support Mousavi,

I knew we had to come out and help them," she said. "People truly believe that change is on the way." If supporters of the conservative incumbent Mahmoud Ahmadinejad were present they were keeping their heads down. Instead the street was filled with hundreds of young, expectant Mousavi supporters in his green campaign colours and chanting slogans hoping for change. Students Fasilat Nassiri, 23, and Behrad Parvar, 25, were queuing with friends who all said they were voting for Mr Mousavi. "Refusing to vote is not an option," said Ms Nassiri. "I don't think things will suddenly change but there is a glimmer of hope. We have to seize that."