Avril John was nine years old when she overheard a conversation in a train station that would stick in her memory. She and her family were on their way from Northumberland in the north of England to a small town in the Midlands called Rugeley, where a modern coal mine had just opened.

The year was 1960, and her father was one of many miners moving to the area for work. They were met at Birmingham station by a man from the National Coal Board. “I will always remember, for all I was only nine, how he said to my dad that [the mine] had just opened and it was guaranteed work for 100 years.”

Thirty years later, the mine closed. In 2011, the US online retailer Amazon opened a warehouse the size of nine football pitches right on top of it. When John, by then a 60-year-old, applied to work there, no one was making the kind of promises given to her father all those years ago: “At the Job Centre, it was stressed that it was till Christmas, possibly Easter, and maybe, maybe, a permanent job at the end of it. When I went to do my tests for the agency, it was stressed again: maybe.” None of her new colleagues should have been surprised when their jobs didn’t prove to be permanent, she says.