Workers at 2 Sisters Food Group factories in West Bromwich and Wolverhampton are voting on strike action over pay and an “alleged culture of beatings and bullying”.
The union Unite said a proposed pay increase of 20p an hour was “derisory” given that the majority of the workforce earnt just £6.22 an hour.
It also said seven day a week shift patterns would upset the work-life balance of the workers, and at two sites in West Bromwich a plan to charge workers £8 a week to park their cars would cancel out the proposed pay increase.
The union added there was a culture of “alleged beatings and bullying” at the plants.
“The dispute centres on a hardline management that is keen to squeeze even further the incomes of workers whose pay is barely above the national minimum wage,” said Unite regional officer Des Quinn.
“There is also a very unpleasant culture at these plants, generated by a number of serious issues relating to alleged bulling and beatings.”
The ballot on strike action is due to close on 7 December.
A spokesman for 2 Sisters Food Group said: “We are very disappointed with the reaction of Unite to ballot for strike action, as we have only had very initial discussions on how we can work together to remain competitive in a tough economic climate.
“The food industry remains challenging, as evidenced by recent events elsewhere in the industry. We will continue to consult on our proposals with unions and employee representatives, working together to ensure our sites can remain competitive for the future.”
On the allegations of bullying, he added: “We take any allegation of this nature extremely seriously and we have proper channels to raise such concerns, including an employee ‘Speak Up’ helpline and daily coffee shops. We also have independent ethical audits at every site, none of which have raised any evidence.
“This is a very serious allegation but we have not been made aware of any specific evidence by Unite.”