Roger Hayter wrote:

Then the experts (see Robin's post in this thread) reckon a short spur
of 2.5mm^2 from your cooker switch or the junction box to a socket will
be ok provided you have no bigger than a 32A MCB.

I checked back through the thread and found that, just after I posted the
question. Thanks for reinforcing it, and to Robin and all the others who
responded. Much appreciated.