A Pak n' Save supermarket in Clendon, South Auckland, has blamed its staff for there being no chicken for sale, a union spokesperson said.
A notice addressing customers signed by management was taped to a shelf usually stocked with chickens for purchase, stating that due to industrial action the supply of chicken was affected.
Lisa Fox, spokesperson for FIRST Union, which represents the distribution centre workers, said blaming staff had angered workers at the company's distributions centres.
"Pak n' Save's attempt to blame workers taking strike action for their own failure is a cynical tactic by a nasty company", she said.
Ms Fox said the union had documents which revealed the real reason there was no chicken available was because the company had contracted the chicken distribution out to another company.
The union are currently in a dispute with Foodstuffs, the company that owns both Pak n' Save and New World over what they claim are repeated refusal to recognise long-serving labour hire staff as employees.
Ms Fox said the company had outsourced its chicken distribution to a new company, "probably as an attempt to make current staff worry about their job security.
"But now the new contractor can't fulfil orders and the company is blaming their own staff," she said.
Last month workers at the former chicken distribution centre site went on strike to protest the company's failure to address labour-hire issues.
But after returning to work the chicken delivery operation returned to normal before the company decided to outsource the work, Ms Fox said.
Chris Quin, spokesman for CTD Nesdale, a Foodstuffs-owned distribution centre of frozen food, said the sign was incorrect.
"The sign an employee put in a store chiller was not correct, as the disruption relates to the change in supply, not union negotiations".
Mr Quin said as a result of a recent supply change to meet demands some stores had experienced disruptions in their chilled and frozen products.
No staff roles were affected by the changes, he said.
"The claim that this is somehow a threat to staff is incorrect".
The union want Foodstuffs to apologise to workers for the misleading statement and inform supermarket customers of the real reason for the inconvenience.
Mr Quin said the sign had been removed and they apologised for any confusion.