Had this Muppet bounce in

They walk amongst us...

get it right, they interbreed!

no they dont,apparently they cant be arsed walking and drive instead

I've always understood that, once issued, a test certificate is valid until it expires even if it subsequently fails a test.
But the problem is that it's unroadworthy (to some degree or other) and it's on record as such so the driver can't pretend he doesn't know.
So I 100% agree the car shouldn't be driven but, if it is, the offence of driving without an MOT certificate has not been committed.

We send our MOT reminder s out at the earliest opportunity if the vehicle passes they have extra days on the certificate if it fails it still has a valid MOT to drive

That is upto government  however you have point we do this because the workshop is busy and can take up to 10 days for repairs and free retest I did fail one on 4 tyres customer said my MOT is still valid though yes ? It is however it's not for the 4 illegal tyres 

That's because it is still MOT'd. This is simple, and I can't grasp why people have so much trouble understanding. The government already clarified it. When you get an MOT issued it lasts 12 months, but is no guarantee of roadworthiness. That used to be stated on the certificate. I haven't checked to see if it still is. If it gets MOTd before that time is up and fails, the original MOT is STILL VALID. The failure is a refusal to issue a certificate in the vehicle's current condition, not a cancellation of anything. If the defects make the vehicle unroadworthy, it cannot be legally driven, even though it has a valid MOT.
Simple? Not simple?

The idea was that the big bold black print stating the vehicle is not to be driven until repaired on the refusal certificate was supposed to make it clear. There is only so much that can be done if the owner is determined to drive it. I have had a vehicle who's brake pipe fractured during the roller brake test, and when the customer returned at the end of the day he drove it away with no brakes. He was never going to listen to anyone.

I'm not splitting hairs with you here aylesburyjock but all vehicles have dual braking systems so he would have had some braking ability albeit reduced. 
Argumentative, no points for that post LOL