Your service fuse may be 80amp. If so, 16mm is fine. However, to comply with the table in the regs, you would still need a 16mm earth.
. Therefore you should use at least 25mm tails and 16mm earth.
why exactly do you need to extend these tails anyway?
cant see how thats scotish powers fault though
out of interest did scottish power also do that terrible termination on the bottom of the isolator?
Also i notice that you seem to have removed the cover from the output terminals of the isolator without turning it off first. In general this is not reccomeneded. Especially if you haven't opened the enclosure before or you know the wiring in there is badly done.
How long is the total run from the cut out to the consumer unit ?
Regardless of this I personally would just install 25mm L&N and a 16mm earth.
Hall Of Shame!!!
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