More than 100 MPs have signed a letter to the Prime Minister asking her to intervene in changes which Sainsbury's is planning to make to thousands of its employees' contracts.
According to Labour MP Siobhain McDonagh, who wrote the letter to Theresa May, the modifications will see 10 per cent of Sainsbury's staff lose up to £3,000 per year.
The changes involve cutting paid breaks, shortening night shift premium hours, scrapping Sunday premium pay and axing bonuses due to shop floor staff.
"Staff describe morale at the store as at an all time low, with many concerned that they cannot afford to stay in the job that they love, despite having worked at the organisation for decades," wrote McDonagh in the letter to May.
"At Prime Ministers Questions, you assured the House that you would look at this issue, recognising the hard work that these staff put in day in and day out.
We ask that you speak directly with the chief executive and call on him to ensure that no staff will face a pay cut under his contract changes, showing a fraction of the loyalty to his staff that they have shown to him.
A petition on Change.org, started by a Sainsbury's employee under the pseudonym of Michelle Cooper, has gathered more than 100,000 signatures asking the supermarket's chief executive Mike Coupe to reconsider his position.
Yet Sainsbury's has maintained that it is in fact raising employees' salaries.
“We are more than happy to explain our proposals to invest well over £100m in our Sainsburys store colleagues. These include a pay rise from £8 to £9.20 per hour, which is an increase of 30 per cent over four years. This would make Sainsburys the highest paying retailer in the country," said the supermarket's retail and operations director Simon Roberts.
"The changes are about having one fair and consistent contract for all colleagues. This isnt the case currently and we have many examples of colleagues working side by side in store, doing the same job and being paid differently, depending on when they joined.
We dont believe that this letter accurately reflects how the vast majority of our colleagues are feeling. We have conducted meaningful consultation with around 100 colleague representatives and have made a number of changes to our original proposals based on their feedback.
"These changes mean that even more people will be better off. 93 per cent of colleagues – well over 120,000 people – will now benefit immediately. For most colleagues thats a pay rise of over eight per cent. And everyone is guaranteed to earn at least as much as they do today until March 2020. We will then review pay again in March 2020.
"It is extremely disappointing that our plans to make Sainsburys colleagues the best-paid in retail are being deliberately misrepresented to such a degree and we would be happy to set the record straight."