Tesco is facing disruption as pre-Christmas strikes are being planned by 6,200 depot staff, unless an agreement over pay is reached with staff.
The union Usdaw said 5,000 members have rejected a 4% annual pay rise, to which Tesco says is a fair offer.
The 5,000 Usdaw members will join members of the Unite union to strike at a total of 13 Tesco distribution centres out of 22.
Joanne McGuinness, national officer of Usdaw, said members had “sent a clear message.”
“We hope that the company is listening and that they will return to the negotiating table with a better deal that is acceptable to our members.
“Industrial action and possible stock shortages in stores in the week before Christmas can be avoided. It needs the company to engage positively in talks with Usdaw and we stand ready to reopen negotiations.” she said.
A Tesco spokeswoman said their customers can be confident they will fulfil it plans over the Christmas period.
“Our distribution colleagues have worked tirelessly through the pandemic in order to keep products moving for customers.
“The pay offer we have made is a fair recognition of this,” she said.
“At the very least the UK’s largest and wealthiest retailer should be making our members a decent pay offer.
“Unite always prioritises the jobs, pay and conditions of its members and it will be giving its full and total support to our members at Tesco until this dispute is resolved.”