According to the Independent:

===
Warehouses to stockpile food for a no-deal Brexit may be empty because they have been snapped up by Amazon to pounce on the UK market, an inquiry by MPs has been told.
The Food and Drink Federation warned that all available frozen and chilled space had been taken – but no one knew who had taken it and whether there was anything in it.

"What we don’t know is whether there is actual product in those places," said Ian Wright, the federation's chief executive.


And he added: "There is some gossip, and I can't stand this up, that quite a lot of this has been booked by Amazon for their entry into the food market at some point over the next few months"

===

Well, what a surprise: Of course there will be a shortage - the famed 'market forces' make the supply of space more or less match the demand, so if there is a sudden sharp rise in demand there will inevitably be a shortage. Nor is much more space likely to appear, unless suppliers are convinced this is not a short term effect, because none of them want to end up with lots of unbought space when the short term demand passes.

I doubt if it is Amazon, in particular. Every single potential purchaser is in competition with the rest for space, and Amazon just happens to be one with the resources to do what it wants. That's how it works. I do not claim Amazon are deliberately targeting the others - it is simply doing what it needs for its business plan, and that's that.

I am reminded of an event in about 1980. A friend was sent by his company on one of those teamwork and management courses. There were some six teams and they each had to build a bridge out of straws, paper, paper clips, sellotape and so on. Instead, he bought up the entire supply of straws and thereby prevented everyone else from completing the task unless they were prepared to pay his exorbitant prices. When the course leader and the other teams claimed he was cheating, he simply replied that's how capitalism works.