Supermarket giant Woolworths has told customers it doesn't expect any "immediate" impact on stock levels at its stores in two states, after a strike by warehouse workers.
Up to 1500 unionised workers at three of the retailer's distribution centres in Victoria and another in NSW walked off the job indefinitely on Thursday.
The workers want better pay amid a cost of living crisis and an end to a performance framework the United Workers Union says pushes them to work faster in ways that risk safety.
With Christmas just over a month away, the union warned the liquor, frozen and refrigerated goods shelves at Woolworth could run bare unless its conditions are met.
UWU Logistics Director in Melbourne Dario Mujkic said workers would strike 24/7.
"When one warehouse takes strike action, we start to see empty shelves in Woolworths supermarkets ... this is five warehouses," he said.
"We will start to see bare shelves of liquor, frozen and refrigerated goods ... pretty quickly."
But Woolworths, and its distributor Primary Connect, said there would be little impact.
"We are not expecting any immediate impact to stores in Victoria and NSW as a result of the industrial action," a Woolworths spokesperson told AAP.
"Stores in other states will not be impacted as they are serviced by their own local distribution centres."
The union is demanding equal pay and conditions across Woolworths' distribution centres and is seeking to bring all workers up to at least $38 per hour in the first year of a new workplace agreement, with percentage wage increases in following years.
Primary Connect said it had already put forward pay offers above local market rates, inflation and the award.
The union is also calling on Woolworths to scrap a performance framework across its centres, which it said pressured workers to cut corners and work unsafely.
Jakob, a worker at Erskine Park in NSW, said staff were given an optimal time to complete a task and once it is done, they were ranked out of 100.
He said this had negative impacts on workers' wellbeing.
"You wake up, you think, how am I feeling today? Can I go to work and can I hit 100 per cent?" he said.
"Then you're at work, you're worried about keeping it up to 100 per cent with all the variables throughout the day.
"Then you finish and you're worried about resting up and recovering for your next shift where you're going to have to hit 100 per cent and it's simply not realistic to do that every day for the term of someone's employment."
Melbourne worker Tim Seiuli, a packer for 16 years, said the framework was "really unsafe".
"We do this every day, day in and day out, we can see unsafe practices people have to take to reach the target," he told reporters.
However, Primary Connect argued the performance framework monitored how long it took to move products and was not about watching staff.
The spokesperson added expectations were based on "the time it should take a person with reasonable skill, applying reasonable effort, working at a safe and conscientious pace, that can be maintained for the duration of a shift, to complete a task".
Mr Seiuli called on Woolworths to come to the table and negotiate for a fair agreement and vowed to continue striking until then.
"We're willing to take it all the way," he said.
Lifeline 13 11 14
beyondblue 1300 22 4636
