As it becomes ever more apparent that Iran's elections were rigged the dangers inherent in any dictatorial political system, notably one that wraps itself up with religion, are brought to the fore. The term "Islamic government" is being made a mockery of.

The Iranian demonstrators of 1979, whose children are demonstrating today, would not have dreamt that the turban was simply going replace the crown and that Iran would go from one repression to another. However, it is not the labelling of a state as "Islamic" that makes it just or unjust, but its structures: does it have sufficient checks and balances between the branches of government, is the leader accountable and replaceable by the people freely; are the people sovereign or the clerics?

Iran's political set up is an Islamist's fantasy – on paper at least – by virtue of having an all-powerful imam, or supreme leader, who claims to acts on behalf of God and is accountable to him and a board of clerics that also claims divine legitimacy. Neither is appointed by elected representatives, and so no analogy can be drawn with judges appointed to the US supreme court. The imam is above the law. The imam and his appointed clerics determine what God wants on all major issues. The prophet is used as the example to justify this set-up. However, whilst the Prophet Muhammad was a supreme temporal and spiritual leader, Islamic law and ethics holds that no one else can claim that role of divinely-mandated political leadership. Strip religion away and this set-up in Iran is a façade. It is based almost entirely on the goodwill and wisdom of the individual holding the post. If you want a imam, or as Sunnis might term it, the caliph, fine, but it needs to be on a par with a "constitutional monarch" – independent from party politics and acting under and not above the law, having no power and respresenting the dignity of the state.

But such are the dangers of theocracy that the arbiters of what is and is not acceptable are not the people, but the religious scholars. And in particular, the religious scholars who happen to comprise the ruling regime. Iran, for example, has many clerics who utterly oppose the current arrangement.

As I have argued before, the role of religious scholars is to provide the moral conscience of society – to act as a modern-day pressure group. Not to seek elected office, play piety politics or corrupt themselves and their message. People should be free to be persuaded by them or to reject their advice, which is often varied – no two scholars agree on everything and thus to impose one Islamic opinion over another as more "Islamic" is very, how can I put it, un-Islamic.

With every day that passes, Iran's Islamic government has less and less legitimacy in the eyes of its own people. It will therefore need to become more and more oppressive to survive – and so the downward spiral continues. Either that or it loosens its grip.

We should be clear that most Iranians do not currently want an end to the Islamic republic. They are not all asking for a western-style secular liberal democracy. What they want is the freedom to elect their own leaders like anyone else. Iran is a great nation with a great history. Iranians will work out their own form of democracy that reflects their own culture and traditions. However, all this is being denied to them right now.

The incumbents are presenting dissenters as agents of America or "Zionists". President Obama is spot on in trying to ensure America (the "Great Satan") does not become a tool with which to further bludgeon reformers. Again the regime is making a fool of its own people: firstly by producing such an exaggerated victory for Ahmadinejad; and secondly by suggesting that reformers are being inspired by foreign agents. As if the former prime minister (Mousavi) and two former presidents (Rafsanjani and Khatami) are British agents or Zionists!

It is also disappointing to see some campaigners for justice outside Iran whose distrust of America or Israel is so entrenched quickly providing mealy-mouthed excuses for the oppression being meted out by the regime. Your enemy's enemy is not always your friend. Dictatorship, whether it is propped up by the west (as in Egypt), or opposed by the west (as in Iran), is wrong. Iranians – like anyone else – should be free to elect whoever they want and learn from their own mistakes. And whether the oppressor wears a turban or a crown, he remains an oppressor.