Flat twin cable with sheathed CPC.

[timhoward]

I bet they are delighted at Quickwire, they finally get a 2.5 sq mm junction box out and then the every day standard cable spawns an alternative!

 

[IAmSparkytus!]

6193B

I’m sure I’ve seen an LSF round cable used on sites before as well with an insulated earth. Not flex, something a bit more substantial but not FP either, didn’t seem to have the outer sheath where you can sort of score then bend slightly to make to snap and strip (if that makes sense)