A second day of industrial action has begun at the Kerry Group plant in Charleville, Co Cork, following an escalation of a dispute over changes to work practices.
The 68 workers in the Cheestrings production section of the plant, which employs more than 250 people, voted in January to take industrial action after being balloted by their union, SIPTU.
In a statement, SIPTU Organiser Terry Bryan said the decision for industrial action was taken following a management decision to withdraw from a Workplace Relations Commission hearing last November, which the union says is in breach of the agreed resolution procedures at the company.
The disputed areas include changes to shift patterns and terms, job rotation and appointments.
A Kerry Group spokesman said the company had made every effort to resolve the dispute throughout 2016, having engaged in 11 local meetings, attended the WRC on seven occasions and once with the Labour Relations Commission.
He said the company had introduced changes to working procedures and schedules across the plant, which had been accepted in all the other departments.
He said the cheese string brand is a highly competitive area and company is determined to secure the future of the brand and met the needs of customers.
A further 24-hour stoppage is planned for Thursday with the threat of further stoppages in the weeks ahead.