Shabana Mahmood has announced that Iran's Islamic Revolutionary Guard Corps will be designated a threat to national security, using powers that make expressing support for the organisation a criminal offence carrying up to 14 years in prison BBC. The Home Secretary is acting under the new National Security (State Threats) Act, the fast-tracking of which the prime minister promised in April 2025.

Draft regulations can now be laid before Parliament. The designation stops short of full proscription under the Terrorism Act 2000 — the mechanism used against groups such as Hamas or National Action — but achieves a similar practical effect for the IRGC specifically: membership, expressions of support and material assistance become offences in their own right.

Alongside the IRGC, the government is proscribing two further organisations under the same package: the Islamic Movement of Companions of the Right (IMCR) and the volunteer corps of Russia's GRU foreign military intelligence agency BBC. Home Office minister Angela Eagle told the Commons that the Home Secretary is satisfied the statutory test is met for all three bodies.

Eagle set out the case against the IRGC in some detail, describing it as a central component of the Iranian state's security apparatus, answerable directly to the Supreme Leader. Its role, she said, extends well beyond that of a conventional military force to encompass intelligence-gathering, the use of proxy actors, and the projection of Iranian state influence abroad BBC.

The move follows sustained pressure from parliamentarians and, notably, from the London Assembly, which in March called on the government to proscribe the IRGC outright, citing at least 20 credible threats linked to the organisation in the UK London Assembly. An Early Day Motion tabled in the Commons in early March made a similar demand, condemning the IRGC as a state-backed terrorist organisation EDM 65341. Neither instrument compels government action, but both signalled the breadth of cross-party appetite for it.

The UK has been an outlier among comparable jurisdictions on this question for some time. The EU proscribed the IRGC as a terrorist organisation, according to London Assembly meeting papers from earlier this year, and Argentina designated it a terrorist organisation at the end of March, aligning itself with the United States Reuters. As recently as 2023, the Independent Reviewer of Terrorism Legislation noted that the UK had not proscribed the IRGC at all, a gap successive home secretaries left unresolved for years despite periodic pledges to act.

That reluctance had a legal logic to it, whatever one makes of the politics. Proscribing the IRGC as a whole under the Terrorism Act would have meant treating it as equivalent to a domestic terrorist organisation, with awkward knock-on effects for the UK's formal diplomatic relationship with Tehran and for anyone caught up in ordinary commercial or state-to-state dealings touching the IRGC's sprawling economic interests. The state threats designation route, created specifically for this purpose, allows ministers to target the security threat without collapsing the distinction between a hostile state actor and a non-state terrorist group.

Parliament still has to approve the draft regulations before any of this takes legal effect. Given the cross-party pressure that preceded the announcement, opposition in the Commons looks unlikely, though scrutiny of the drafting — particularly around the boundaries of what counts as "support" for an organisation as economically and politically enmeshed in Iranian statecraft as the IRGC — will bear watching in committee.

The inclusion of the GRU's volunteer corps points to a parallel strand of state threats policy aimed at Russia, run on much the same statutory basis as the Iran measure. Together with the IMCR designation, the package signals that ministers intend to use the new Act as a standing tool against hostile state-linked networks generally, not as a one-off response to Iran alone.

For businesses, universities and diaspora organisations with any dealings that might touch IRGC-linked entities, the practical question now is where the line falls between the criminalised "support" and legitimate activity — guidance from the Home Office is likely to matter as much as the regulations themselves once they clear Parliament.