Just had a look on the EV&TCP Panel site and its very strange but I cannot seem to find it on there now for some reason. Perhaps its been removed. It went along the lines if you overstay in the shop/cafe for too long a period you would be issued with a fine.
If this is the Abergavenny store, maybe because the shop is so near the town area they are having people using this car park for that reason and not putting money in the council run car parks. This would cause Morrisons smallish car park to be filled up quickly and not leave room for their own potential customers. This probably wouldn't happen at the Ebbw Vale store as it is not near any town but it maybe worth being aware of any store car parking policy not to get caught out. With all the social distancing measures in place it also takes longer to shop and queue at the checkouts so that adds on to the time people are in the store. That gives us Food For Thought!