Leaving aside any legal ramifications, you cannot be expected to drive a vehicle which you believe is unsafe.
Phone Motability tomorrow and tell the person that you speak to on their helpline that you are not prepared to continue to drive a vehicle that you believe is dangerously defective.
Whether or not the car has been “deemed safe” by Peugeot, the fact that you are afraid to drive it and carry vulnerable passengers in the vehicle must be the deciding factor.
Tell Motability in no uncertain terms that you will not drive the car again and expect them to arrange collection of the vehicle.
In all my dealings with Motability I have found them to be very helpful and sympathetic when they realise that your mind is fully made up.
Let us know how you resolve this ‘Windy’. Stay strong.