You can still have an unroadworthy vehicle under C&U Regs, even if you have a current MOT.
You can fail a C&U inspection on non-MOT items, even as your vehicle is in the MOT test bay.
A <Fail> invalidates the current MOT certificate, but...
The rules change on 20 May, so get studying now.
Incidentally, an expired MOT could result in a fine, but you wouldn't get points.
New MOT Rules: