Thanks for all the comments so far.
Update - after using half a tin of WD40, 2 pairs of pliers which didnt do anything, I've moved onto silicone remove, just appied and need to wait 3 hours; will post an update later.
Would a freeze spray work - thoughts?
http://www.halfords.com/motoring/paints-body-repairs/car-rust-removal-treatment/halfords-shock-unlock-spray-400ml
Soaked in vinegar overnight and dint do a thing. The nut is pretty much corroded on the plastic.
Tried brute force to a point, but if the plastic snaps, i'll have to change the whole unit which is tilled in.
What do you think to taking a hacksaw to the nut?
Help, just moved house and the shower hose has split.
The issue i have is i cant remove it due the the metal nut getting stuck on the plastic screw.
Ive had the shower unit open and cant simply remove the plastic bit either.
Tried 3 in 1 oil... not sure what to do next.
Here is a...