You can put your car through its MOT up to a month before the previous one runs out right..
So, if it fails that MOT, do you still have a month to get it repaired, or do you have to get it sorted straight away?
This would suggest the later, but just want to check..
"If your vehicle fails the test
You’ll get a ‘notification of failure’ from the test centre if your vehicle fails the test. The failure will be recorded in the secure central MOT database.
Until it passes a retest, you can only drive your vehicle:
to a pre-arranged appointment at a garage to have the repairs done
to a pre-arranged MOT test appointment"..