365. No punishment without law under the European Convention on Human Rights.

The European Convention on Human Rights provides that no-one shall be held guilty of any criminal offence on account of any act or omission which did not constitute a criminal offence under national or international law at the time when it was committed, and nor shall a heavier penalty be imposed than the one that was applicable at the time the criminal offence was committed1. The prohibition is a 'Convention right' for the purposes of the Human Rights Act 1998 and it is therefore unlawful as a matter of English law for any public authority to act incompatibly with