proscription

Terrorism and free speech: the criminal law and the Convention

17 March 2026 by Guest Contributor

By Samuel Talalay

Introduction

Article 10 of the European Convention on Human Rights (“ECHR” or “the Convention”) provides qualified protection for speech. Section 12(1A) of the Terrorism Act 2000 (“the 2000 Act”) criminalises certain speech acts relating to proscribed organisations. In the case of R v ABJ; R v BDN [2026] UKSC 8 the Supreme Court was asked to decide whether these two things could be reconciled: is s 12(1A) of the 2000 Act compatible with the Convention?

In its judgment, given on 26 February 2026, the Court answered this question with an unequivocal ‘yes’. The offence introduced by s 12(1A) was prescribed by law and necessary in a democratic society. Crucially, conviction would always represent a proportionate interference with the defendant’s Article 10 right to free speech where the elements of the offence, properly understood, were made out.

In providing such a resounding answer, however, the Court risks setting the bar too high for legislative provisions to be compatible with the Convention.