Unite said its members at the company, formerly Dalepak, were angry over detrimental changes to terms and conditions, including reductions in paid breaks and holidays.
Talks will be held to avoid a possible industrial action at the firm in Northallerton, North Yorkshire.
Sarah Mitchell, regional officer, Unite, said the proposed changes are detrimental to the workforce.
“Our members have unanimously rejected the unacceptable changes and requested that we proceed to an industrial action ballot,” she said.
“We have a further meeting with the management tomorrow at which we hope to reach an agreement, thus negating the need for industrial action.
“However our members are strongly committed to getting an acceptable and fair settlement – and this includes taking industrial action.”
The 150-strong workforce can gain extra holiday days for length of service, but the union says management wants to ‘buy out’ those days.
The union said the North Yorkshire company, which produces burgers, sausages and grill steaks, is also attempting to write the union’s recognition agreement out of employees’ contracts.