On Friday, the Iranian regime will try to bring people to the polls to manoeuvere whether to keep the incumbent Hassan Rouhani in office or to replace him with his leading challenger, Ebrahim Raisi.

But despite the Supreme Leader Ali Khamenei's blunt and threatening appeals to the population, the regime may see much less participation in the electoral process than it hopes for. Dissident groups led by the the People's Mojahedin Organisation of Iran (PMOI) have been organising a mass boycott of the elections, in order to call attention to the public demand for free elections and an end to the country's repressive theocracy.

Widespread non-participation in the 19 May elections would be a serious blow to the clerical regime's claims of legitimacy.

It would also expose the depth of resentment harboured by the Iranian people about a system in which not only do the opposing political factions not represent prospects for different policies, but also don't offer to make any changes in the current conditions the Iranian people are faced with.

If you want to better understand why change in the executive system does not bear fruit to a change in the government's behaviour, you need only ask those who have served long sentences as political prisoners, spanning more than one presidential administration.

Hassan Rouhani
A supporter of Hassan Rouhani wears a scarf bearing his image at a campaign rally Atta Kenare/AFP/Getty Images

I personally fit this category, having been arrested in 1981, at the age of 17, for supporting the PMOI (MEK) and distributing its publications. I served an 11-year sentence, half of it in solitary confinement. I was put in prison during the presidency of the hardline Ali Khamenei, now the regime's Supreme Leader, and bore witness to the presidency of the supposedly "reformist" Akbar Hashemi Rafsanjani from behind bars.

Neither I, nor any of my fellow political prisoners experienced an improvement in our conditions or witnessed any increased leniency in the Iranian judicial system after the transition from one administration to the other. With the shift toward more "moderate" leadership, activists and advocates for true democracy continued to be rounded up arbitrarily and subjected to torturous interrogations and long periods of imprisonment on vague charges like "insulting regime officials" or "enmity against God."

Iran election
Supporters of Hassan Rouhani distribute brochures ahead of the election Atta Kenare/AFP/Getty Images

Admittedly, in terms of the raw amount of bloodshed, the period of Khamenei's presidency is unparalleled. There is one primary reason for this: In 1988, while I was still in the middle of my sentence and still being tortured on a regular basis, the regime's founder Ruhollah Khomeini issued a fatwa aimed at destroying the PMOI and thoroughly suppressing resistance to the weakened theocracy in the waning days of the Iran-Iraq war. As a result, approximately 30,000 political prisoners were hanged during that summer.

Though many of them had finished serving their official sentences, they were brought before a kangaroo court in rapid succession and given an opportunity to totally disavow their former political activities. Those who failed to do so were summarily put to death.

At the height of the massacre, as many as 400 people were killed in a single night. When all was said and done, out of more than 10,000 inmates who were held on political charges in Evin Prison along with me, only 250 individuals survived. I was slated for execution as well, but the abuse I had suffered in previous weeks led to my hospitalisation, and when authorities came to my cell looking for me there was no trace and I was spared in the midst of the mass executions.

Ayatollah Hossein Ali Montazeri, who was Khomeini's designated heir as supreme leader before he was ousted from the regime, condemned the mass executions as "the worst crime committed in the Islamic Republic."

It is the darkest stain on Iranian contemporary history which remains essentially un-addressed to this day. Although the Rafsanjani administration has the luxury of claiming innocence regarding the actual executions of Khomeini's fatwa, the fact that it took office just one year after the massacre, means the administration held prime responsibility in covering up the crimes perpetrated by its predecessors.

In fact, Rafsanjani's presidency was associated with its own brand of violence, including assassinations of PMOI activists abroad and attacks on Western targets by Hezbollah and other terrorist proxies.

Ebrahim Raisi
Iranian presidential candidate Ebrahim Raisi speaks at a campaign rally in Tehran Atta Kenare/AFP/Getty Images

But despite such crimes, its retroactive responsibility for the 1988 massacre is obvious. If the choice for the Iranian people is between a political faction that will commit murder with impunity and a faction that will ignore and justify those murders to its dying breath, there is no choice at all.

The silent conspiracy that was initiated during Rafsanjani's tenure continued through its three successors – those of the other so-called "reformist" Mohammad Khatami, the firebrand Mahmoud Ahmadinejad, and the "moderate" incumbent Hassan Rouhani, who is striving to defend his civil rights credentials as he seeks a second term.

Very early in the current administration, Rouhani destroyed any credibility he may have had as a defender of human rights when he appointed Mostafa Pourmohammadi as his Justice Minister. Pourmohammadi was one of four judges on the ''Death Commission'' in Tehran which decided on the fate of political prisoners and who would be sent to the gallows in 1988. Sitting by his side during the massacre was none other than Ebrahim Raisi, the supposed main rival to the sitting president in the current election cycle.

This fact serves as well as any other to illustrate how little separation there is between the two accepted factions within the Iranian regime. In turn, it also explains to a significant extent the reasoning behind the tremendous success of the PMOI's campaign, calling for the boycott of these sham elections.

Graffiti has popped up across Iranian cities proclaiming the people's readiness to vote for "regime change," as have posters depicting the president-elect of the National Council of Resistance of Iran (NCRI), Maryam Rajavi.

Last year, the conspiracy of silence surrounding the 1988 massacre was effectively broken when a recording of Ayatollah Montazeri was released online. Social media activity from the Iranian community inside and abroad has helped to keep the discussion of that incident alive in spite of the regime's earnest efforts to suppress it once again.

Now, with these and other crimes at the forefront of the Iranian's public consciousness, the stage is set for the people to categorically reject the regime's claims of legitimacy. And the international community should similarly reject the parody of democracy that Tehran will attempt to put on display in Friday's masquerade.