The UK government has proscribed Iran's Revolutionary Guard Corps (IRGC) after attacks on the Jewish community and Iranian dissidents, Sky News first reported on Monday.
Ministers fast-tracked the National (State Threats) Bill, as promised by the prime minister. The existing legislation to proscribe terror groups did not extend to state-backed groups.
It will now be a criminal offense to invite support for, or express an opinion or belief that is supportive of, the IRGC; assist the IRGC in carrying out UK-related activities or engage in conduct likely to materially assist it; or accept or retain a material benefit provided by or on behalf of the IRGC.
The aim is statedly to "disrupt individuals who promote the interests and objectives of designated bodies".
Breaching the new law could result in up to 14 years in prison and/or a fine.
Fight must continue against IRGC network
"That is not a decision to celebrate without asking why it took this long, but it is the right one, and I welcome it," Roger Macmillan, a former director for the Iranian diaspora site Iran International, told The Jerusalem Post.
"Proscribing the IRGC is the floor, not the ceiling. The real fight now is against the network around it: the front charities, the so-called Islamic centers and education centers that launder its ideology into British communities, the online broadcasters and the social media influencers who do Tehran's work for it. None of that stops because one organization has been added to a schedule."
Macmillan said the proscription of the IRGC must now be matched with the political will and resources to support the Police and the Security Services in actively going after networks and bringing people to justice, "not just designate an organization on paper."
"Today is the right first step, many years too late. The hard work starts now."