Rationing was in place because of the war, and not lifted until long afterwards as you say. That is not the same as introducing it in peacetime, which would be politically difficult.

And totally unnecessary! Why bring up such an irrelevant issue which no-one has ever mentioned as being the remotest possibility?

Stockpiling would only be to cover a possible temporary shortage of a few days while importers readjust their suppliers, and is only being considered as a precaution unlikely to be needed at all.