Foad Izadi is not a man given to dramatic predictions or the headline grabbing soundbite.

A carefully spoken and intelligent assistant professor at Tehran University, Iran's most iconic academic institution where generations of students have played such a pivotal role in political movements and revolutions in this country's history, he is a man who is a seasoned and calm observer of Iran's political scene.

Which is why I was taken aback by his reply when I asked him what was so significant about Friday's landmark parliamentary election.

"Because it is a referendum on the Islamic Republic itself," he replied.

Tomorrow's vote goes to the very heart of what Iran's Republic means - not just to Iranians themselves, but to Iran's role and place in the world.

This may sound melodramatic, but it's very true.

First of all, just consider the scale of the poll.

It is the first serious and meaningful test of the mood of the country eight months on from the landmark nuclear deal between Iran and major world powers including the UK - and two months after decades long sanctions on Iran were lifted.

The vote has been described as 'pivitol'. Credit: Reuters

All over Tehran, walls are plastered with campaign posters and leaflets of the 1,000 candidates vying for the 30 seats representing the capital.

Across the country 55 million Iranians, half of them women (most under the age of 35) will vote on the composition of the next Iranian parliament, known as the Majlis.

What's more, they will have a real choice between two very different visions about what kind of country Iran wants to be and what kind of foreign policy it will follow.

People walk during a ceremony marking the 37th anniversary of the Islamic Revolution, in Tehran. Credit: Reuters

The candidates are from two political blocs:

Those religiously orientated and politically conservative parties who mistrust more open relations with the West, and feel Iran must continue with the revolutionary Islamic doctrine that was born during the revolution of 1979.

And reformist candidates, loyal to the government of President Rouhani, who negotiated the nuclear deal with world powers, and who want to see a greater openness inside Iran and its relations with the outside world.

This in itself is remarkable because nowhere else in the Middle East would you find an election where people are presented with a genuine choice.

A supporter of Iranian former vice-president Mohammad Reza Aref. Credit: Reuters

No one is pretending that the elections here are a Westminster-style democratic poll.

After all, candidates have been vetted, and some reformists have complained that they have been barred from standing.

But in a region where elections are just a rubber stamp of autocracies and absolute royal rulers - Iranians are being presented with a semblance of a choice between two alternatives.

'Nowhere else in the Middle East would you find an election where people are presented with a genuine choice' Credit: Pantea Vasseq/DP

Why does it matter?

Because only a few years ago, Iran was led by the controversial hardline President, Mahmoud Ahmadinejad and was regarded as a dangerous pariah state.

Now barely a few years later, the British Embassy has been reopened in Tehran, the Chancellor of the Exchequer George Osborne and countless other western leaders are planning to lead trade delegations to Tehran, western tourists are flocking to the country.

And there is a real atmosphere that a lasting strategic corner could be turned in Iran's longer term place in the world.

The Iranian president Hassan Rouhani. Credit: Reuters

But if the reformists do badly, and the conservatives win, this would be a disaster for the reformist government of President Rouhani.

He will find it difficult to get his foreign policy past the parliament and the brakes would be put on closer dialogue with the West.

That's why this election is seen as a pivotal one.

I asked Foad Izadi if he was willing to give me a prediction of what he thought might be the outcome.

"I think that come Monday, Mr Rouhani will be a happy man and so will his reformist allies".