The Co-operative Group is to use fingerprinting machines to track staff hours.
The society plans to install biometric data collection terminals in its food stores over the next two years to record the working hours of its 55,000 staff.
The system would reduce the amount of time managers spend dealing with schedules and absences and complying with legal requirements on breaks, maximum weekly hours and minimum rest times, the company said.
A spokesman denied it was a Big Brother system, insisting it was "simply a more efficient way of running our stores".