Ongoing production of XXXX beverages in Queensland is in doubt with staff being notified the brand's Brisbane brewery will close.
Management from Japanese controlled parent-company Lion notified staff in June the Castlemaine Perkins brewery in Milton would be shut down, United Voice coordinator Damien Davie said.
But a spokesman for Lion, the food and beverage giant that owned Castlemaine Perkins, said the brewery would not close and was in fact looking to hire more staff.
"In fact, there will be pay offers on the table - on top of the best pay and work conditions in brewing in Queensland," the spokesman said.
"We simply want the ability to bring on additional people in summer when we brew more beer, this is how every other seasonal manufacturer operates, but our current agreement is confusing and prohibitive."
The brewery is currently in talks with the union over new pay agreements.
Mr Davie said other workers had received threats the plant would close if negotiations to scrap full time jobs in favour of labour-hire, part-time and casual positions were unsuccessful, .
"The continued push to bring in labour-hire employees and casualise the workforce is the main reason cited by management when threatening workers with closing the plant," he said.
"A large proportion of XXXX is now made at the Tooheys Brewery in Lidcombe, Western Sydney.
"XXXX Gold is also made at West End in South Australia and in some circumstances even at the Boags Brewery in Tasmania."
The Lion spokesman said the current pay agreement was 24 years old and needed to be updated.
Doubts about the future location of the brand's production coincides with the end of its long term sponsorship of Queensland's State of Origin team after Wednesday's final 2017 game.
AAP with Rachel Clun