An Asda worker of 15 years from Leeds said many staff will leave the company following 'Contract 6' proposals - which would see workers 'forced' to work flexible hours.
The worker, who has chosen to remain anonymous, said the new proposals were the biggest change of contract in her 15 years with the company.
She said staff who had childcare issues or specifically flexible hours would be forced to leave due to the changes.
-> 'The founders would be spinning in their graves': Trade union slams new Asda contracts as 'thousands face sack'
The worker said: "We didn't get told very long ago.
"We were told the new contract was called Contract 6 and all of the changes.
"I have worked here for such a long time.
"It is not a nice thing to do to any of us."
WHAT GMB SAY
Today (August 5th), Neil Derrick, GMB Regional Secretary Yorkshire and North Derbyshire, said the founders of the supermarket would be "spinning in their graves".
Mr Derrick said: “Asda was formed from a Leeds family company, one built on the proud Yorkshire values of hard work and respect.
“The founders would be spinning in their graves if they saw how workers are being treated now - threatened with the sack.
“Loyal staff face giving up work so they can look after elderly parents and disabled relatives, single parents are contemplating giving up their only source of income – and long-serving, dedicated workers are being rewarded with cuts to terms and conditions. It's not good enough.
“Asda doesn’t have to do this - it’s a multi-billion pound company and its workforce deserves a better deal.”
On Sunday, Gary Carter, GMB National Officer, said it was a "total outrage" that Asda bosses were threatening staff with the sack.
Mr Carter added: "Shoppers will be horrified to learn of what is going on behind the scenes.
“Asda is a multi-billion pound company, it doesn’t need to bully staff out of their hard won terms and conditions.”
-> Outrage as thousands of Asda staff 'facing the sack' over new work contracts
The worker said she is currently on a regular contract with the store which allows her hours to be flexible.
However, new proposals would mean staff would work on bank holidays and weekends compulsory.
She added: "I have lost the flexibility.
"Not many workers can be flexible now.
"People have children and work around all types of circumstances currently but won't be able to in the future.
"I think a lot of staff will leave unfortunately.
"They can change our hours at any time, it is not fair."
CONTRACT 6 EXPLAINED
Currently there are 6 types of contracts Asda staff could be on - even if they work in the same store.
Asda is proposing to merge contracts 1 to 5 into one contract known as Contract 6.
The contract terms require workers to be flexible about when and what times they work.
The contract also involves working weekend and bank holidays.
It has caused concern for many of the 60,000 members of staff in Asda stores across the country.
Another Asda worker, who also wished to remain anonymous, said 'nobody likes the proposals'.
The worker, speaking today (August 5th) said: "They can change our hours any time they like.
"They have to give you a certain amount of notice but how long is that likely to be?
"We were paid for our breaks before, but not anymore.
"We don't know what is happening.
"It is going to affect every member of staff in the stores, there is a lot of confusion."
WHAT ASDA SAY
A company spokesman said: "The move enables us to streamline our existing contract base from 6 different contract types to 1, bringing us in line with industry standards and ensuring that everyone doing the same job is on the same contract.
"Over 50,000 colleagues nationwide were already employed on this contract before we opened consultation to standardise the contract base.
"In an extremely competitive retail landscape, this contract enables us to have the right colleagues in the right place at the right time to deliver great service to our customers.
"We’ve listened to the counter proposals from the GMB and our National Colleague Voice groups and extended the collective consultation period to continue the discussion.
"As a result of the collective consultation process, we have made changes to the proposals, including amending the break rules to minimise the impact of unpaid breaks and increasing the minimum period required to ask a colleague to change department or working pattern to 4 weeks.
"We have also agreed a transitional payment for 18 months for any colleagues who would be financially worse off.
"Overall, the proposal represents an investment from Asda of over £80m.
"We are currently working through the proposals with our colleagues to understand their individual circumstances and how this contract would apply.
“This new contract will see Asda invest in a pay increase for over 100,000 retail colleagues, as well as enabling us to deliver better service to our customers in an intensely competitive marketplace.
"We are continuing to talk to our colleagues about this change and to understand what it might mean for their individual circumstances.”