During this grave national emergency (which will surely get worse) it's wrong to leave something as important as food distribution to companies whose first motivation is profit after all their executives get bonuses based on profit.
Supermarkets are lapping it up, they're making a fortune, they love us to panic buy.
So Mr Johnson. Act now, seize the means of food distribution, give households (& relate to number occupants) a grocery spending limit and a single delivery or collection slot per week. Close the big stores* to walk ins to allow the staff to focus on deliveries and collections.
Oh, and implement price controls on key items.
* leave the small convenience stores alone (defined as the ones that can open longer on a Sunday) they can continue to provide a good local service for local walk ins.