My car was written off as a Cat N - do I have to get it re-tested for an MoT?

I know insurers require a new MoT for a vehicle that was a Cat N write off. They have given me 14 days to obtain one but is it a legal requirement? Could I still drive on the existing MoT? Also if it fails...

Are Cat N cars more expensive to insure?

Is insurance higher on Cat N write off vehicle?

My car has been written off but I want to get it repaired - where do I stand?

My car was damaged by another driver and they have admitted fault. I have been to the garage and they advise that the car is likely to be written off because of the cost of the repair (it is likely category...