FMOTL - Magna Carta 1215 and constitutional theories
It remains that some people (sometimes known as Freeman of the Land - aka FMOTL) continue arguing a case based upon a strange interpretation of the UK constitution. This ends up with a strange distinction between common law and statute law and an attempt to argue really quite unorthodox things.
I am not in itself opposed to things which are unorthodox, but if people do not follow the procedures defined in the UK constitution they should not expect anything to come of this. I know of a case where someone's mental capacity was removed for relying on this. I believe that decision to be wrong, but whatever it may be it does not help.
Every so often people try to rely on these theories. Can I emphasise:
I have never heard of anyone succeeding in the UK on the basis of FMOTL legal theory. I am quite happy to look in the comments at something.
The most important point to understand is that the UK constitution is based upon a popular revolution from 1688. The constitutional settlement that was achieved at that point and accepted at that point is the constitutional settlement mutatis mutandis that applies today. That settlement included Magna Carta 1297 not Magna Carta 1215.
Magna Carta 1215 did not even last for a year even though it was supposed to last for ever. It is a "dead parrot" in a legal sense.
Hence the foundations of the legal theory known as FMOTL are flawed and any edifice built on them has to fail.
You can find Magna Carta 1297 on the legislation website if you wish.