Thanks Frank.
I spoke to the supply co (British Gas). When I started talking about distances from meter of the consumer unit, permissions etc. they didn't seem to know what I was talking about. All they seemed concerned with was that the de-energising of the meter for the Consumer Unit move be booked with the metering company for my area through them.
I've also searched for sub Main Switched Fused Isolator and the nearest I could find is 100A Metal Clad Switchfuse - S.P. from
QVS Is this the right kit? Does it need to be double pole, single throw?
Many thanks