The UK is a common law country. It is a widely held belief of many people that statute Acts of parliament (i.e. most 'laws') only apply with the "consent of the governed"; and that one may be a "free man of the land" or a "Scottish Sovereign".
They assert that only common law applies to them, i.e. laws surrounding assault, threat or theft. Statutes such as the Road Traffic Act are seen as enacted by the private corporation of 'parliament'; and since they don't consent to being governed, these 'laws' don't apply to them, e.g. speeding.
Going one step further, free men and other groups of people state they have a right to travel under the Magna Carta, and since Blacks Law defines 'driving' as doing so commercially; they're entitled to drive ("travel") non-commercially without insurance.
Has such a defence ever held in court? If you look on YouTube you'll find plenty of people who believe it will.