Belgian lawmakers gave initial clearance on Wednesday to a prisoner exchange treaty with Iran that could lead to the release of an Iranian diplomat convicted of planning to bomb a rally of an exiled opposition group.
The foreign relations committee of Belgium's lower house debated the treaty for more than six hours over two days before finally approving it.
The measure still needs to be put before the full 150-member lower house of parliament, most likely in the next two weeks, but the chamber normally follows votes of its committees, given they have similar party compositions.
The prisoner exchange might secure the release of a Belgian aid worker who was detained in Iran in February and could help Swedish-Iranian academic Ahmadreza Djalali, who has taught in Belgium and been sentenced to death in Iran.
Iran has called for the release of Assadollah Assadi, sentenced to 20 years in prison in Belgium in 2021 over a foiled 2018 bomb plot. His was the first trial of an Iranian official for suspected terrorism in Europe since Iran's 1979 revolution.
It is not clear when a prisoner exchange might happen.
Several lawmakers voiced concern that the treaty, as proposed, might lead to "hostage diplomacy" and put other Belgians at risk of detention.
The exiled National Council of Resistance of Iran (NCRI), whose 2018 rally near Paris had been the bomb plot's target, called the treaty "shameful" and said Assadi should remain in jail.
"If he had succeeded, hundreds would have been killed," Farzin Hashemi, deputy chair of the NCRI foreign affairs committee, said during a protest of about 100 NCRI members near Belgium's parliament.
"The experience of the past four decades has shown that making concessions to a terrorist regime will only embolden it and endanger the lives of more innocent people," he said.
The Islamic Republic has dismissed all terrorism accusations, calling the Paris attack allegations a "false flag" stunt by the NCRI, which it in turn considers a terrorist group.
(Reporting by Philip Blenkinsop; Editing by Mark Heinrich)