Is there any issue with a single 2.5mm 3093Y cable in a 20mm pvc conduit (secured to surface with metal saddles) used for a radial to supply a twin-socket in a garage from a 20 amp MCB?
Well, being soft it will be a bar steward to push in but you should be able to pull it in with draw cord. I'd not push current rating much above 20A, as cooling will be poorer than open air.
I assume the local environment is OK for the conduit, so it would be OK for singles , and therfore it will be OK for the cable.
Do not try and be clever and get two in, it will not fit. At the ends you need to make the flex fill the terminals that may be designed to suit solid core - if need be crimp ferrules may be useful.
This is the preferred sort of thing to do for vehicles and so forth, so I cannot see a problem with it static.
