Trust me, it's got nothing to do with saving lives but it has everything to do with the Blairites making £300 a time for certification
Not to mention the money made from fines on those who inadvertently breach the regulations.
It's interesting that it is claimed that 8 deaths and 550 serious injuries are caused each year by faulty wiring. It's unclear of cause how many of those are caused by badly installed wiring (as opposed to old or vermin-damaged wiring, for instance).
As a comparison, there are supposed to be 20 deaths and 250 serious injuries per year caused by old and worn-out electric blankets. These deaths are mainly of old people. If saving life were the real reason for Part P, then before that was enacted, it would have been made a criminal offence to possess an electric blanket that was damaged or over 10 years old.