Around 90 warehouse staff went on strike at 6am today for 24 hours in a bid to get a 4.2% pay increase.

According to Unite, the employees went without a pay rise last year, while the rest of the business received a 2% increase, because the company thought its warehouse staff were "already paid too much compared to other warehouse workers", Unite said. Those employees have been given a further 2% rise this year, the same offer that was made to the striking employees.

However, unite national officer Steve Sibbald said that the offer was unsatisfactory to its members, who rejected it.

He said: "The rest of the group received a 2% increase last year and 2% this year and our members want the same increase, having gone without an increase last year when everybody else got one.

"The company is doing well, it recorded an 8% increase in profit last year, on the back of a £500m turnover, so our members believe they are well within their rights to ask for 4.2%."

A spokeswoman for OUP said: "We believe we have made a very fair and reasonable final offer and are disappointed at the outcome of the ballot. OUP has been keen to maintain constructive dialogue with Unite representatives throughout the negotiation. However, despite extensive discussions, we have as yet been unable to reach agreement."

A further two days of strike action is planned for next week.