The industrial action is currently scheduled to run for 12 weeks, with employees walking out every Friday, after 92.4% of employees voted to take action.

According to Unite regional officer Gillian McKay, the plant's management have failed to negotiate changes to terms and conditions, on employee contracts, with the union.

She told PrintWeek: "This has really been building up for the last six months. They have two new managers in there who don't know what they are doing. They don't know anything about negotiation."

McKay said a collective agreement has been in place for over 30 years at the Livingston plant, but that management imposed new contracts of employment without consulting the local Unite.

She added: "In recent negotiations the employer refused to accept our members’ right to reject their offer and then proceeded to impose the new terms without any notice.

"These new contracts of employment will make employees work for longer with no salary increase and remove all flexible working arrangements. It would seem API management are touting themselves as poster-boys for the botched Beecroft Report with this dictatorial agenda.

"We have tried to get the chief executive to intervene but there has been no resolution to this dispute."

A spokeswoman for API Foils told PrintWeek the company would be making a statement shortly.