Question to the Home Office:

To ask Her Majesty's Government what is the definition of Left, Anarchist and Single-Issue Terrorism, as referred to on the MI5 website.

Our definition of terrorism is set out in section one of the Terrorism Act 2000. It defines terrorism as: the use or threat of action; which is designed to influence the government or an international governmental organisation, or to intimidate the public or a section of the public; and which is made for the purpose of advancing a political, religious, racial or ideological cause.

The action used or threatened must involve serious violence against a person, serious damage to property, endangering a person’s life, creating a serious risk to public health or safety, or the intention to interfere with or seriously disrupt an electronic system. This definition is threat agnostic and kept under regular review to ensure it remains fit for purpose, including by the Independent Reviewer of Terrorism Legislation.

It is a matter for the intelligence agencies and police to determine how the definition is applied in counter-terrorism investigations.