Belgian prosecutors asked a court to impose a 20-year jail sentence on the Iranian spy Assadollah Assadi, as the trial on the "state-sponsored terrorism" behind a Paris bomb plot began on Friday. Mr Assadi, who was an accredited diplomat in Austria, boycotted the hearing on the grounds of diplomatic immunity. The court however pressed ahead with the trial, in which he is accused of directing a married couple to carry out a bombing against an Iranian opposition meeting near the French capital. The couple, Nasimeh Naami and her husband Amir Saadouni, face 18 years in prison, and prosecutors asked for 15 years for a fourth accomplice, Iranian poet Mehrdad Arefani. “They knew very well what they were getting into," said the federal prosecutor. The court was told Mr Assadi was the leader of a terrorist organisation and the mastermind behind the planned attack, as a veteran of the Iranian Ministry of Internal Security (MOIS). “He often consulted with his superiors in Tehran. He worked for MOIS Department 312, which the European Union has earmarked as a terrorist organisation. "He continues to play the victim, and refuses to recognise the authority of this court. He did not at all behave the way a diplomat should behave and took advantage of his privileges.” The prosecutor declared at the outset the plot to set off a bomb at a Paris conference was a “clear case of state terrorism". The couple started receiving payments from Iran in 2015, the same year they met their new handler "Daniel", identified as Mr Assadi. The prosecutor said they had acted purely for financial gain. “They continue to minimise their actions and take no responsibility. I will take into account their co-operation with the investigation," said the prosecutor. <strong>Orders from above</strong> The plaintiffs believe that Mr Assadi organised the plot on orders from Iran’s highest authorities. "The Iranian state conspires, threatens and carries on attacks and executions," said lawyer Georges Henri Beauthier. "We have irrefutable proof that the Iranian state gave orders from Tehran and authorised the deaths of thousands of people."<br/> The alleged target was the annual gathering in Paris of the dissident group, the National Council of Resistance in Iran (NCRI), attended by about 25,000 people. But the plot was stopped on the same day when a pan-European police operation followed up on a tip from a foreign intelligence service. Ms Naami and Mr Saadouni were arrested in Brussels on June 30, 2018, as they were driving to the rally in Villepinte, outside Paris. Police discovered an explosive in Ms Naami's make-up bag.<br/> Later that year, the French government accused Iran's intelligence service of planning the operation, a charge the country has denied. Mr Saadouni’s lawyer, Wouter Smet, said he would make the case that the pair were victims of coercion. “My client is extremely nervous," said Mr Smet. “He has co-operated with the investigation from the start, but fears he will not be believed.” Mr Saadouni says he was pressured to work with MOIS. He reportedly was first approached by Iranian intelligence services after a student protest in Iran. When Mr Saadouni’s father realised MOIS agents were looking for him, he arranged for his son to come to Europe in 2003. There, he joined the People's Mojahedin Organisation of Iran (MEK) and met his future wife a year later online. According to his lawyer, Mr Assadi believes he should not have to appear in court because he retains diplomatic immunity. The trial is still taking place in his absence. Mr Assadi has accused the civil plaintiffs of trying to turn the case into a political trial on behalf of the opposition movement. The co-defendants sat behind their counsel, surrounded by masked policemen. Mr Saadouni, wearing a face mask, his hair pulled back, and Ms Naami, wearing a white sweater, listened closely as the NRCI’s lawyers presented their arguments. The lawyers representing NRCI members argue there is enough evidence to suggest the four defendants plotted against the organisation. “All four of them knew they were plotting an attack. Everyone had a specific role. There is no better example of an organised terrorist plot,” said lawyer Rik Vanreusel, who urged Mr Assadi to appear in court. “Assadi has shown himself to be a fundamentalist who believes opposition should be eliminated. He went as far as to threaten the investigators. According to a police document, he has claimed that there would be retaliation if the outcome of the trial is unfavourable.” Mr Assadi's lawyer Dimitri De Beco has disputed this allegation. According to Mr Beauthier, who is representing the interests of the NCRI, there is no doubt the plot is “a clear case of state terrorism”. He said: “Assadi was the essential link, instructing the couple carrying a bomb weighing 550 grams, and Mr Arefani, who had infiltrated the opposition group. "These people, who were posing as opponents of the regime, have travelled to Iran on numerous occasions. Mr Assadi has paid them substantial amounts of money for their work.” Rik Vanreusel, also representing the NCRI, rejected statements made by Ms Naami. “She claims she didn’t know the package contained a bomb”, Mr Vanreusel said. “If that were true, how does she explain the messages she exchanged with Assadi, hours before the planned attack? "She sent him the following text message: ‘The team will win, God willing, uncle.’ "If she thought she would be setting off fireworks, why would she have sent these messages? The bomb did not look like fireworks. "She also failed a lie-detector test. I believe Ms Naami was a secret agent in the first place. She manipulated her husband to lie to investigators."<br/> Mr Vanreusel emphasised the continuous support Mr Assadi has received from Iran. "In jail, he was often visited by Iranian officials. They've never stopped supporting him." The next hearing of the trial is scheduled for December 3, with a verdict expected by the end of the month or early next year.