Somerfield faces union action after store staff voted against accepting new terms and conditions.

A ballot of union members was counted this week and staff told management that they were not in favour of changes to contracts that would create standard terms, such as the removal of premium pay on Sundays and bank holidays. Currently staff are subject to one of 16 different contracts, due to past acquisitions.

Shopworkers' union ­Usdaw said it was setting up a meeting between national officer Joanne McGuinness and Somerfield management. McGuinness said they would be discussing the implications of the ballot results and possible options. However, the union would not confirm whether strike action was a possibility.

A Somerfield spokesman added: "We are currently considering our response and will continue discussions with the union."

The ballot comes as part of a wider restructuring of store staff. In an attempt to modernise, Somerfield intends to create a flatter structure, which could result in the removal of an entire layer of store management.

As well as ditching premium pay, changes to terms also include no sick pay for the first six months of work and the restructuring of holidays with all staff to get 30 days, including eight bank holidays that could be taken on the days or another time.