Woolworths' looming sale or closure of its Masters hardware chain has left thousands of workers and their families facing an "uncertain future", unions say.
Australia's retail union – the Shop, Distributive and Allied Employees Association – said up to 9,000 Masters workers were grappling with the grim news after waking up on Monday.
"This is obviously a devastating time for workers and their families," union national secretary Gerard Dwyer said.
"The SDA will be doing everything we can to support them during this uncertain period."
Mr Dwyer said Woolworths had assured him that its preferred outcome was to sell the business.
"If this is achieved the SDA will promptly engage the new owners on behalf of our members," he said.
"If a sale cannot be secured, we'll be ensuring that every possible avenue for redeployment of Masters' dedicated, hard-working employees is explored."
Woolworths announced on Monday that it was looking to either sell or wind up Masters and Home Timber and Hardware after heavy losses.
Although the union referred to up to 9,000 workers affected, Woolworths put the figure at 7,000.
There are 63 Masters stores in Victoria, NSW, Queensland, South Australia, Western Australia and the ACT.
Mr Dwyer said Woolworths was a large company with a "good track record" of re-deploying staff where brands have been closed or down-"sized.
"The union has already sought and been given assurances that Woolworths would be working closely with staff and the SDA to maximise redeployments should the business have to close," he said.
"We can assure staff that all employee entitlements will be protected whether the business is sold or closed."
The union would have representatives available to support Masters employees and their families and urged employees to contact their SDA branch.
The National Union of Workers, which represents Masters warehouse staff, said people's livelihoods were on the line.
State secretary Gary Maas said the welfare of hard-working employees must be a "serious consideration" in decisions about the brand's future.
"We want to see workers engaged in discussions in the future about what will happen to the workforce who, through no fault of their own, are in a predicament at the moment where they don't know what will happen to their jobs," Mr Maas said.
Woolworths chairman Gordon Cairns said the company would endeavour to find jobs for its 7000 Masters staff within the Woolworths empire if the chain was not sold as a going concern.
"Today will come as a shock to those 7000 people, and to be quite frank, they've done an outstanding job at Masters – they're not contributory to the fact we're not making money," Mr Cairns said.
"We feel very strongly that as a repsonsible and caring employer, our objective is to make sure we can do the best thing by them and do the best we can to find them employment in the [Woolworths] group."
The decision to pull the plug on Masters came after a review started in September showed it was years from returning a profit.