All duty managers at Sainsbury's supermarkets have been put on a 12-week redundancy plan and are having to reapply for their jobs as part of a radical overhaul of its management structure.
The changes, which will result in some job losses, will see duty managers replaced by deputy store managers.
All of Sainsbury's estimated 500 stores have a store manager but currently there are also two duty managers in stores that take £500,000 a week while some higher-taking stores have three duty managers.
Under the new structure stores taking £750,000 a week will be allocated two deputy managers, while those stores taking less will have one deputy manager.
"Our business has evolved considerably since we last reviewed our in-store management structure," said a Sainsbury's spokeswoman.
"The time is right to implement a new structure that can be reviewed as the business develops further and is even more focused on the customer. At deputy store manager level, we are doing everything we can to ensure that we limit the number of redundancies but unfortunately we don't need as many deputy store managers as we have current duty managers and this means that a redundancy situation will arise in some locations."
However, she said, Sainsbury's primary concern would be to work with colleagues to consider suitable alternative roles.
The shake-up also means stock control managers are to be scrapped, but a new commercial manager role is to be created, looking after the administration side of the business. The stock control management role is to become part of the dry goods management role.
The nightshift team is to have a duty manager added to its shift, so each store will have a duty manager and a nightshift manager.