Morrisons has warned it may close three depots at the centre of strike talks, with the loss of 2,500 jobs.
The sites in Bristol, Aylesford in Kent, and Warrington were "at risk of closure" after a review indicated they "may no longer be required", it said.
Staff at the depots had voted to walk out over job cut fears, but a planned strike this week was delayed to allow more talks between the firm and unions.
The supermarket said it hoped to re-employ as many staff as possible.
Ongoing discussions
Morrisons says it has "overcapacity" in its depot operations because it has now sold off 200 former Safeway stores.
It bought Safeway for Ј3bn in 2003, and had to dispose of a number of shops to meet competition requirements.
Others have since been sold because they did not fit Morrisons' needs.
"Many and varied options have been considered and each has been thoroughly assessed," said Morrisons warehouse and distribution director, Chris Noone.
"These recommendations follow a detailed review of each depot's operational circumstances and fit within the network; and an appraisal of their ability to service the group's future distribution needs.
"We are currently discussing the proposals and consulting with all those concerned with a view to agreeing a plan for the best way forward."
Union anger
The GMB union strongly attacked Morrisons' announcement, accusing the supermarket of failing to involve either the workforce or the unions.
"Morrisons have conducted themselves in an underhand, dishonest and disgraceful way," said GMB national officer Jude Brimble.
"GMB believe that the review has been built on a conspiracy of deceit and deception."
A Morrisons spokesman said it did not wish to reply to the GMB's comments, but insisted the company was continuing to consult with the unions.
(BBC)
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