Proscribed Terrorist Organisations

The government can proscribe organisations that it considers engage in or promote terrorism. When an organisation is proscribed, it becomes a criminal offence to belong to it or to support it.

This briefing describes the recent history and present status of proscribed organisations under the Terrorism Act 2000.

Proscription under the Terrorism Act 2000

Prior to the Terrorism Act 2000, proscription was exclusively concerned with terrorism connected with the affairs of Northern Ireland. Under the 2000 Act, proscription was extended to include organisations concerned with both domestic and international terrorism.

The Home Secretary can proscribe an organisation if they believe it is “concerned in terrorism”. If the Home Secretary believes that an organisation meets this statutory test, they must then decide whether to proscribe the organisation. In doing so, they take into account various policy considerations.

Consequences of proscription

The 2000 Act sets out a number of proscription offences. These include:

• belonging to or inviting support for a proscribed organisation
• arranging or assisting with the arrangement of a meeting that supports a proscribed organisation
• addressing such a meeting
• wearing clothing or displaying articles in public which arouse suspicion of membership or support of a proscribed organisation.

The maximum penalty for these offences (except wearing clothing or displaying images) is 10 years’ imprisonment and/or a fine.

The government can also impose financial sanctions on proscribed organisations.

Current proscribed organisations

As of December 2025 there were 84 international terrorist groups proscribed under the Terrorism Act 2000 and 14 organisations in Northern Ireland proscribed under previous legislation. The most recent proscription orders concerned Palestine Action, Maniacs Murder Cult and Russian Imperial Movement.

In November 2021 the government announced that the government had laid an instrument to proscribe Hamas in its entirety; previously, the only the military wing of Hamas had been proscribed (since 2001).

In September 2023 the government laid an instrument to proscribe the Wagner Group, a private military organisation which has acted as a proxy for the Russian state. The government considered it to be involved in committing acts of terrorism, including in relation to its involvement in Russia’s invasion of Ukraine.

In January 2024 the government proscribed Hizb ut-Tahrir, a Sunni Islamist political organisation with the long-term goal of unifying Muslims worldwide and establishing a Caliphate under Shari’a law. The government assessed that it is currently concerned in terrorism, and that articles were posted on its website celebrating and praising the 7 October 2023 attack by Hamas.

On 23 June 2025 the then Home Secretary, Yvette Cooper, announced that she had decided to proscribe Palestine Action, a pro-Palestinian group which aims to support Palestinian sovereignty by using direct criminal action tactics to halt the sale and export of military equipment to Israel. An order proscribing Palestine Action, together with Maniacs Murder Cult, and Russian Imperial Movement, both white supremacist groups, came into force in July 2025.

The annex to this paper includes a current list of proscribed organisations and a description of their activities.

Criticisms of the proscription regime

Proscription has been characterised as a powerful deterrent, a way of tackling lower-level support for terrorism, and a signal of rejection by society. But questions have also been raised as to its utility in combating terrorism and its compatibility with the rule of law.

The former independent reviewer of terrorism legislation (IRTL), Lord David Anderson KC, repeatedly recommended the introduction of time limits for proscription orders, as have his successors, Max Hill KC and the current IPTL, Jonathan Hall KC.

However, the government has so far declined to follow these recommendations and currently de-proscription is done by way of application only. As a consequence, groups that no longer meet the statutory requirements for proscription continue to be proscribed; Lord Anderson described this as “an affront to the rule of law”.