Foster's Group has hit back at claims by unions that up to 200 employees are set to take industrial action at its largest brewery in Australia.

Noel Jago, Foster's general manager at the facility in Yatala, said that the LHMU, AMWU and ETU were "deliberately misleading the public by suggesting that the vast majority of the company's workforce would walk off the job.

"The three unions involved have just conducted a secret ballot over a proposal to take protected action," he said. "However, what the unions haven't communicated is that only half of the 295-strong workforce at Yatala are actually union members and therefore participated in the vote.

"Of that number, only 93 people voted in favour of taking industrial action, with a majority of these indicating a preference for four-hour stoppages.

"This translates to just 31% of the Yatala workforce voting in favour of the action, hardly the 'vast majority' to which the unions keep referring in their vocal campaign against us," he said.

"Only union members will be able to participate in the action, which means that whatever happens, at least half of our workforce will still be on the job."

Jago said that Foster's was yet to receive notification of when and where the action would take place.

"However, we have a highly flexible supply model in place and have been preparing for the possibility of industrial action with some contingency planning," he said. "We are well placed to service the needs of our customers over this time and can reassure customers and consumers that we will do everything in our power to ensure a continuation of supply."

Jago added that Foster's had recently put a new wages offer to its 295-strong workforce that amounted to a 14% increase over the next three years, plus a range of other benefits, and the company was hopeful of shortly reaching a solution that is acceptable to the company and its employees.

He said that the Yatala site had only ever had Employee Collective Agreements with its workforce since it commenced operating 19 years ago.

"I can assure you that all Yatala workers are free to be members of a union, and unions are welcome to represent their members in the enterprise bargaining process to assist in delivering a mutually agreeable outcome," he said.

"However, our position remains that we would always prefer to have a direct agreement with our workers - as we have since our inception over 19 years ago."

The facility is the largest of three breweries operated by Foster's in Australia, and brews beers across the company's portfolio, including VB and Crown. With 300 employees, Yatala has an annual capacity of over 50m nine-litre equivalent cases.