But where is the legislative authority for including restrictions on movement in an Order? This Order was made purportedly, as stated in the first sentence of the Order, pursuant to s 70(1)(f) and (m) of the Health Act 1956. Prohibition of congregating is allowed, but there is no reference to prohibiting movement.
Permitting people to move outside their residences for the purpose of exercise is so obviously desirable that, if on strict interpretation there is an absence of statutory power to make orders regulating people’s movements, some justification needs to be found. Enforcement requires lawful authority. Constitutional lawyers will point to a shift in what Kelsen called the Grundnorm, according to which near-universal public acceptance of rules is what gives them de jure status. Radical indeed, to the point of being revolutionary (and indeed this idea is used to explain successful revolutions). However, such an esoteric constitutional and jurisprudential concept, like arguments that endeavour to bridge the gaps that sometimes occur between law and common sense (or, if I might be permitted to add another language, la réalité), is unlikely to be well received by judges.
Obviously the power to regulate movement needs a source in legislation.