Supermarket chain Kwik Save has closed a third of its stores across the UK, leading to up to 700 job losses.
The chain has struggled against cheaper rivals
The group posted "closed" signs at 79 stores in areas including Wales, Scotland, Northern England, the North West and West Midlands.
Last week, Arla Foods stopped delivering milk to the struggling chain because of "payment problems".
Speculation has suggested Kwik Save is facing a cash crisis, despite getting a £50m rescue package in February.
"This is a huge number of closures which will affect many workers," said a spokesman for the union Usdaw.
"We will be seeing an urgent meeting with the company to clarify what redundancy package workers can expect as well as discussing the long-term future of the business."
The ailing chain will be left with just 147 outlets after the closures - a far cry from the mid-1990s when it had more than 1,000 shops worth more than £1bn.
KWIK SAVE CLOSURES
WALES - sites including Bangor, Holyhead and Rhyl
YORKSHIRE - 10 sites including Selby, Ilkley and Doncaster
WEST MIDLANDS - Blackheath, West Bromwich
On Tuesday, customers turned up at the group's store in Wellington, Shropshire to find a note at the shop announcing its closure - 12 jobs have been lost at the site.
In a statement, Kwik Save said it regretted the "difficult decision", but had been forced to "announce these cutbacks to secure the future of the business".
The most recent figures from research group TNS, for the 12 weeks to 22 April, showed Kwik Save's share of supermarket spending had shrunk from 1.2% in 2006 to just 0.2% a year later.
Kwik Save used to be part of the Somerfield supermarket group, but last year Somerfield's owners sold off the loss-making brand and most of its stores to new company BTTF and rebranded the 100 Kwik Save sites that it kept.
Retail expert Theresa Whickham told the BBC that Kwik Save had failed to keep up with the competition as big retailers moved into the convenience shopping market.
Other analysts have said that the chain has struggled against low-cost rivals such as Aldi and Lidl.
Do you work at a Kwik Save branch that is closing? When were you told about the closures?
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