Ah, good point. Although the case with UK is a bit unusual, in that all those powers are still devolved from the British Parliament (and so it could rescind them with a simple majority vote in theory... though that would surely trigger a constitutional crisis now) - so technically it's not federalism.
In contrast, most federations designate who has the power to enact criminal law in their respective constitutions.
In contrast, most federations designate who has the power to enact criminal law in their respective constitutions.