... but interestingly they have issued an exception for motorbikes, where aftermarket LED headlamp "bulbs" are no longer a reason for MOT fail. Not too sure of the reasoning behind that decision, if it's OK for a bike then why not a car, they both use regular style H4 or H7 etc.
Also I'm not quite sure of the legality aspects (for bikes). While it may not be an MOT failure that doesn't mean it is "legal" (construction and use etc). Peculiar situation. I've hunted for a statement on the legality but haven't found anything as yet.