Supreme Court rules that broad definition of “terrorism” in Terrorism Act 2000 is not contrary to international law

15 November, 2013

The Supreme Court in its judgment of 23 October 2013, and in an enhanced bench of seven judges, unanimously held that the definition of terrorism in the Terrorism Act 2000 was intended to be wide and could thus include acts by insurgents against the armed forces of a state anywhere in the world in the context of a non-international armed conflict. The legislation was not to be read down in the light of any alleged rules of international law.

Their Lordships declared, contrary to the appellant’s argument, that there was indeed no generally accepted definition in international law as to what constituted terrorism and in particular that practice as to whether domestic legal systems could designate as terrorism acts of insurgents against state armed forces in non-international armed conflicts was too varied to constitute a rule of international law.

Nor was there any reason to prevent the UK government from going further in legislating than any particular anti-terrorism treaty required. Thus, the statutory meaning of the relevant provision was not to be restrictively interpreted because some of the activities made offences under the 2000 Act were criminalised as a result of the UK’s international treaty obligations. It was for parliament to modify the wide definition of terrorism in the 2000 Act should it wish and not the courts.

Professor Malcolm Shaw QC was one of the lead counsel for the respondents (CPS).

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