By law, the homeowner or landlord must be able to prove that all electrical installation work meets Part P, or they will be committing a criminal offence.
What law? Where does it say that. If there is such a law, what legislation is it written in? As we have already discussed part P simply states an installation must not cause fire or electricuation. How do you propose this can be proved by the homeowner. You are spreading more electricians --------.