Last month, union members at the Sunderland-headquartered commercial printer voted unanimously in favour of industrial action after the company launched a 90-day consultation on cuts to production workers' terms and conditions of employment.

35 staff at the site have staged 24-four hour walkouts every Tuesday and Friday for the last three weeks, but the latest action will see workers stay away for 58 hours.

The walkout will start at 7pm on Tuesday 31 July with picket lines in place from 6.30am until 7pm on 1 and 2 August.

Unite national officer Steve Sibbald said: "We hope the suppliers and customers will put pressure on Paragon to resolve this dispute. The members are reluctant to do this because they are losing money but we will use any pressure-point we can."

Since an initial statement released last month, Paragon has so far not responded to the industrial action or calls for negotiations to resume and Sibbald said if the silence continued the action would be stepped up.

"If they continue to ignore this, we won’t stop with suppliers and clients. We will move on to suppliers and customers further down the chain. We will also move to shareholders if necessary," he added.

Multi-site firm Paragon has an annual turnover of more than £45m and Sibbald said its profitability was a reason for the industrial action.

"Many of our members have accepted cuts to their terms and conditions in the past but the fact that this firm is profitable means they could at least consider maintaining the terms and conditions. What's most important is keeping a enthusiastic work force with high productivity and not chipping away at employment contracts," he added.