I Why not update your fuse box to a Dual RCD protected consumer unit?

I can do this for as little as £200!

A residual current device (RCD), similar to a residual current circuit breaker (RCCB), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions. RCDs are designed to disconnect quickly enough to mitigate the harm caused by such shocks although they are not intended to provide protection against overload or short-circuit conditions. The units I install also include MCBs which protect against overcurrent. RCDs will operate in less than 0.4sec (dependant on type) whereas a re-wirable fuse can take up to 5 seconds.

A big difference when being electrocuted!