you still need a valid mot to tax it though. mot aint a tax, the govt gets around 10 quid a car from the cost of the mot..the rest goes to the mot station.
but heres how the law looks at it,
Use, cause or permit a vehicle to be used on a road without a test certificate is an offence under Section 47, RTA 1988.
Penalty: Fine of up to £2,500 (if the vehicle has 8 or more seats), £1,000 (otherwise). No disqualification, endorsement or points can be awarded.
Re no MOT invalidating Insurance; Because of section 148 RTA 1988
as to condition of the vehicle, Insurance Companies cannot invalidate a certificate issued as far as making it a criminal offence i.e. to use without Insurance (S145). This does not not however prevent them from taking action to recover certain costs under the civil law. Remember the case of the bald tyre? The driver was not charged with using without Insurance. The third party was paid out but the sum was recovered from the driver by the Insurance Company at County Court.
but you would be prosecuted if you were invloved in a fatal RTA, remember the recent case where the kiddies died, his had current mot but was not "allegedly"in a fit state for the road.
why risk it? for the sake of average of 30 quid !