Workers at Pak'nSave Rotorua are preparing to picket tomorrow over claims of mistreatment by senior management.
Members of First Union "unanimously" endorsed a call for industrial action against an alleged "campaign of bullying and intimidation" by bosses - claims which have been refuted by Pak'nSave.
The demonstration is set to take place from 12pm outside the Fenton St store, lasting approximately two hours.
Senior union organiser Bill Bradford claimed management at the store had acted with "a disregard for employment law".
"More than 70 workers from the supermarket have joined First Union, but when we sent the owner a list of members in order for the union to meet them under the Employment Relations Act the owner and his management team responded with a campaign of bullying and intimidation," he said.
But the union's allegations have been strongly denied by Antoinette Laird, corporate PR director at Foodstuffs NZ, which owns Pak'nSave.
"On behalf of Pak'nSave Rotorua, I can confirm the store is in the very early stages of talks with First Union regarding contract negotiations for staff," she said.
"We refute the allegations made by First Union. As a business we are happy to facilitate the union negotiation process, and are keen to work towards discussing an outcome that is appropriate for all concerned."
She expressed disappointment that the union had decided to organise a demonstration this weekend.
In a statement Mr Bradford alleged that "one by one the workers who joined the union were summoned to speak with the store manager and the HR manager. Every worker in a business like Pak'nSave fears a 'call upstairs' - to them it means they are in trouble.
"At each individual meeting members were pressured to leave First Union. Management used tactics like telling members the owner knew who joined the union, the managers then asked whether the member could afford the union fee and suggested the union cannot win a pay rise and better conditions for its members. It is an abuse of power by management and a breach of employment law," he said.
"First Union has filed a claim in the Employment Relations Authority as a result of these meetings. The owner and his management team cannot be allowed to breach employment law because they are fearful of the union's ability to help workers win fair pay and conditions."
Ms Laird said she believed there were more constructive ways to reach a resolution other than taking industrial action, and apologised to any shoppers that may be affected.
"We appreciate our customers' understanding and patience at this time."