On Dec 7, 11:56*pm, Lobster wrote:
To be honest I have no intention of taking this to Building Control but
still want the work to be up to standard.

Extending circuits in a garage or shed or porch is non-notifiable
works.

Search online for 6491X (singles) in cut lengths.
www.tradingdepot.co.uk do 1.5mm & 2.5mm 6491X at 16p & 22p per metre.
I think there is another supplier out there, perhaps another on Ebay.
Perhaps the sheds do a 50m reel (which would be a good length).