Unions in the Stamford area says face masks in stores will help protect staff.
However unions are concerned it could lead to extra stress for workers.
Unions in the Stamford area says supermarkets enforcing rules that customers have to wear face masks in stores will help protect staff.
Tesco, Asda and Waitrose have joined Morrisons and Sainsburys in saying people will be banned from going in if they don't have a covering unless they're exempt for medical reasons,
Unions welcome that but fear it could lead to confrontation with members of the public.
Sharon Langham from USDAW says some are even spat at whilst at work.