The national agreement, which is the first to have been reached between the ink manufacturer and the union, will cover all current collective bargaining agreements.

It will be signed by seven senior Unite workplace reps, covering all sites in the UK and all grades of staff, along with Sun Chemical’s senior management team.

Unite assistant general secretary Tony Burke said: "I welcome this agreement and the work undertaken by the team to secure it.

"This marks the beginning of a new phase in what I hope will be a long, productive and fruitful relationship. We now look forward to working with Sun Chemicals in the interests of their staff and our members."

Unite regional officer, Louisa Bull added: "This agreement is a real breakthrough for Unite members at Sun Chemical. Our reps, members and the management have shown real vision in reaching this agreement.

"I am pleased that staff working for Sun Chemical now have a modern and progressive union to represent them at work and we offer our congratulations to all concerned."

Sun Chemical said that it worked with Unite closely, but it did not wish to add anything more at this time.