Amazon workers are staging the first ever UK strike on Wednesday against the online giant in a protest over pay.
Around 300 staff walked out at Amazon’s Coventry warehouse, the GMB union said, over what they called a “derisory” 5% pay rise to £10.50 an hour.
Workers told the BBC about “severe” conditions, claiming they are constantly monitored and upbraided for “idle time” lasting just a few minutes.
Amazon said it has a system “that recognises great performance”.
A spokesman said it “also encourages coaching to help employees improve if they are not meeting their performance goals”.
Two Amazon workers, who are members of the GMB, said the robots in the warehouse “are treated better than us”.
Darren Westwood and Garfield Hilton described to the BBC how even a trip to the toilet can lead to questions by managers.
“The thing with stopping work is that they want to know why,” said Mr Hilton. “So if the time is beyond a couple of minutes they can see it on the system.”