Terrorism Act 2000


The Terrorism Act 2000 is the first of a number of general Terrorism Acts passed by the Parliament of the United Kingdom. It superseded and repealed the Prevention of Terrorism Act 1989 and the Northern Ireland Act 1996. It also replaced parts of the Criminal Justice Act 1998. The powers it provides the police have been controversial, leading to noted cases of alleged abuse, and to legal challenges in British and European courts. The stop-and-search powers under section 44 of the Act have been ruled illegal by the European Court of Human Rights.

Definition of terrorism

Terrorism is defined, in the first section of the Act, as follows:
Sections and have been criticised as falling well outside the scope of what is generally understood to be the definition of terrorism, i.e. acts that require life-threatening violence.
Prior to this, terrorism was defined in an Act as a footnote, such as Reinsurance Act 1993 section 2:
"acts of terrorism" means acts of persons acting on behalf of, or in connection with, any organisation which carries out activities directed towards the overthrowing or influencing, by force or violence, of Her Majesty's government in the United Kingdom or any other government de jure or de facto.

and Prevention of Terrorism Act 1989 section 20:
In this Act "terrorism" means the use of violence for political ends, and includes any use of violence for the purpose of putting the public or any section of the public in fear.

In the Northern Ireland Act 1996, the criminal offences referred to as terrorism are provided as an exhaustive list of over 70 items.
This move to establish a sound definition of terrorism in the law made it possible to build an entirely new set of police and investigatory powers into incidents of this kind, beyond what they could do for ordinary violent offences.
The inclusion in its definition of the phrase or threat mirrors the common law, as it was codified with respect to written words, in 27 Geo. 2. c. 15 and again in 4 Geo. 4. c. 54.

Proscribed groups

As in previous Terrorism Acts, such as the Prevention of Terrorism Act 1989, the Home Secretary had the power to maintain a list of "proscribed groups" that they believe are "concerned in terrorism". The act of being a member of, or supporting such a group, or wearing an item of clothing such as "to arouse reasonable suspicion that he is a member or supporter of a proscribed organisation" is sufficient to be prosecuted for a terrorist offence.
Under the act aliases of organizations can be added. For example, Al Muhajiroun, Islam4UK, Call to Submission, Islamic Path, London School of Sharia and Muslims Against Crusades were added in January 2010 and November 2011 as alternative names for Al Ghurabaa and The Saved Sect and in June 2014 Need4Khilafah, the Shariah Project and the Islamic Dawah Association were added to this list. An alias does not have to be added to the list for prosecution to be possible, provided it can be demonstrated that for all intents and purposes the organization is a proscribed one, and that the person involved has committed a proscribed act.

List of proscribed terrorist groups

more than 80 organisations appear in Schedule 2 of the Act. They are all listed in Schedule 2 of the act.

List of proscribed groups linked to Northern Ireland-related terrorism

The following 14 organisations have appeared in Schedule 2 of the Act since it came into force. and are listed under the above heading in the Home Office document 'Proscribed Terrorist Organisations' under the collective description "organisations in Northern Ireland that were proscribed under previous legislation". They are armed paramilitary groups proscribed because of involvement in the Troubles;
These have been added periodically since March 2001 by statutory instruments.
In July 2025 three more groups were added by the and are proscribed from 5 July 2025:

Section 41 (arrest without warrant)

Section 41 of the Act provided the police with the power to arrest and detain a person without charge for up to 48 hours if they were suspected of being a terrorist. This period of detention could be extended to up to seven days if the police can persuade a judge that it is necessary for further questioning.
This was a break from ordinary criminal law where suspects had to be charged within 24 hours of detention or be released. This period was later extended to 14 days by the Criminal Justice Act 2003, and to 28 days by the Terrorism Act 2006.

Stop and search without suspicion

Section 44

The most commonly encountered use of the Act was outlined in Section 44 which enables the police and the Home Secretary to define any area in the country as well as a time period wherein they could stop and search any vehicle or person, and seize "articles of a kind which could be used in connection with terrorism". Unlike other stop and search powers that the police can use, Section 44 does not require the police to have "reasonable suspicion" that an offence has been committed, to search an individual.
In 2009, over 100,000 searches were conducted under the powers, but none of these resulted in people being arrested for terrorism offences. 504 were arrested for other offences.
In January 2010, the European Court of Human Rights ruled that stop-and-search powers granted under Section 44 were incompatible with the European Convention on Human Rights. It held that the rights under Article 8 of two people stopped in 2003 outside the ExCeL convention centre in London, which at the time was hosting a military equipment exhibition, had been breached. The Court found the powers were "not sufficiently circumscribed" and lacked "adequate legal safeguards against abuse", contrary to a 2003 High Court judgment upheld at the Court of Appeal and the House of Lords.
Pending new powers in the Protection of Freedoms Bill, Theresa May made a remedial order under the Human Rights Act 1998, which had the effect of repealing sections 44, 45, 46 and most of section 47.

Section 47A

As discussed above, since 18 March 2011 section 44 has been treated as repealed. It has been replaced with a new section 47A by the Terrorism Act 2000 Order 2011. Under the new provisions, searches can only be carried out as follows:
A senior police officer must make an authorisation in relation to a specified area or place. He can make such an authorisation only if he:
  • reasonably suspects that an act of terrorism will take place, and
  • considers that:
  • *the authorisation is necessary to prevent such an act,
  • *the specified area or place is no greater than is necessary to prevent such an act, and
  • *the duration of the authorisation is no longer than is necessary to prevent such an act.
When such an authorisation is in force, any constable in uniform can, in the specified area or place, stop:
  • a vehicle, and search:
  • *the vehicle,
  • *the driver of the vehicle,
  • *a passenger in the vehicle, and
  • *anything in or on the vehicle or carried by the driver or a passenger,
  • a pedestrian, and search:
  • *the pedestrian, and
  • *anything carried by the pedestrian.
But the power to search can only be used for the purpose of discovering whether there is anything which may constitute evidence that:
  • the vehicle concerned is being used for the purposes of terrorism, or that
  • the person concerned is or has been concerned in the commission, preparation or instigation of acts of terrorism.
The power conferred by such an authorisation may be exercised whether or not the constable reasonably suspects that there is such evidence. A person or vehicle searched under this power may be detained for as long as is reasonably required. A person who is searched may be required to remove their headgear, footwear, outer coat, jacket or gloves, but nothing else whilst in public. If requested, a form must be given stating that the person/vehicle was stopped.
An authorisation can be given by an Assistant Chief Constable. Authorisations can also be given by the Assistant Chief Constables of:
If given verbally, authorisations must be confirmed in writing as soon as reasonably practicable, and in either case must be notified to the Home Office as soon as reasonably practicable. Authorisations must be confirmed by the Home Office within 48 hours of their being made, or they expire automatically. If confirmed, an authorisation can only last for up to 14 days. An authorisation can be cancelled at any time, or restricted in respect of the time it ends or the area which it covers, but it cannot be expanded. New authorisations can be made regardless of whether previous authorisations exist, or have been cancelled or have expired.