What's happened

The Home Secretary has declared that Iran's Revolutionary Guard Corps — a military and security force answerable to Iran's leader — is a threat to Britain. Under new law, it is now a serious crime to express support for it, with sentences up to 14 years in prison.

Two other organisations are also being prohibited in the same announcement: a group linked to Islamic movements, and a Russian military intelligence unit.

Why this matters

The Revolutionary Guard is not just a conventional army. It runs intelligence operations, manages armed groups in other countries, and helps project Iran's power worldwide. The government says it poses a direct security threat to Britain.

Why now?

Parliament has been pushing for this for years. In March, London's Assembly listed at least 20 serious threats linked to the organisation within the UK. Members of Parliament formally called for action. Other countries — the EU, the United States, and Argentina — had already designated it as a threat, leaving Britain as an outlier.

Why didn't this happen sooner?

There was a legal complication. The traditional way to ban a terrorist group in Britain would have damaged diplomatic relations with Iran and complicated ordinary business dealings. The government has now used a newer law, specifically designed to target foreign state threats without those side-effects — a cleaner way to protect security whilst preserving normal diplomacy.

What happens next

Parliament has to vote to approve the new rules. Opposition is unlikely given the broad support for the move beforehand.

There is a practical question that needs answering. For businesses, universities, and community groups that might have dealings touching anything linked to the Revolutionary Guard, the question is: where exactly does the law draw the line between illegal support and normal activity? The government will need to give clear guidance when the new rules come into force.