what is the law on testing

[Marnik]

But certification of electrical work, be it a minor works or an EIC has nothing to do with Part P of the building regs. ?
It's a requirement of BS7671 (17th).

The work may or may not be notifiable work, the paperwork however is the same regardless.

Since when?
Part P is a part of the building regulations, has got nothing to do with BS7671 17th edition, Where does it say in the BGB?