It's all about supply and demand, How many workers from Poland are working at this warehouse?
If the warehouse were struggling to find or replace workers they would not dare send anybody home.
It reminds me of men standing outside the mine/docks gates and being picked for a days work, We have gone back 100 years.
At least Jeremy has said he will ban zero hours contracts.
I have news for you there were men standing outside the dock gates and our factory looking for work in the late 1950's
And in the 1970's my job description read
You are not employed on a fixed hours basis, you are required to be available whenever and wherever required.
What did this actually mean? I had as my patch the entire British Isles.
Interestingly my reading of that at the time was that I was actually employed 24/7! on the credit side I was on a fixed Salary
Of course at that time I had never heard of a "Zero hours contract"
And the workforce were to a man and woman described on their contracts as casual labourers, even the skilled men
Casual labour definition:
people who are employed on a temporary , rather than a permanent or regular basis