Trade union Unite is balloting 970 of its members at Kuehne + Nagel Drinks Logistics over strike action.
It complains that the company is imposing changes to working conditions without meaningful consultation.
KN Drinks Logistics handles distribution for a number of major brewers and soft drinks brands. Some 27 sites are affected. The ballot closes on 28th August.
In a statement, KN Drinks Logistics said it had received formal notification from Unite of the intention to hold a ballot for industrial action.
“The Company is fully committed to on-going dialogue with Unite and plans to meet with union representatives on 29th August to discuss the situation further,” it said.