asked the Minister or Food if he is aware that bread rationing coupons inadvertently torn out of ration books by shops are refused by the assistants when their period of validity comes along; and if he will make a ruling to allow shops to accept loose bread rationing coupons

I am not aware that this is happening. One of the early measures taken to ease the burden of bread rationing was to allow retailers to give "change" when selling against a coupon of high bread unit value. This arrangement has not been withdrawn, and it necessarily involves the subsequent presentation and acceptance of some loose bread unit coupons