Cheers for the answers folks. Posted in both forums as I noticed there are a few previously unanswered questions in each and thought it'd be the best way to get replies that'd lead me to a decent solution. I assumed there would be different users here who don't check electriciansukforum. But...
Rocky,
if it makes any difference, one of the tubes is an Energizer T8 (also retrofit/plug and play). This diagram suggests that it works without choke/ballast
seen here: https://www.lampshoponline.com/led/t8-led-tubes-high-quality/t8-4ft-18w-led-tube-frosted-high-output.html
Hello,
I'm currently installing these LED tube lights in my garage (https://www.amazon.co.uk/Fluorescent-Replacement-daylight-ultra-light-unbreakable/dp/B00XN3CGJO) using these fixtures (https://www.simplelighting.co.uk/2-120-cm-batten-fitting/).
I have the fixtures hooked up to mains plugs...