UPS said it had taken “concrete actions” to address claims of bullying and safety breaches at its Gloucester depot after a trade union announced a series of strikes that could hit parcel deliveries.

Unite said it had been trying to resolve issues of “bullying, health and safety and dignity at work” for 18 months and it had been left with no option but to ballot for strike action, which returned a 100% vote in favour.

However, UPS said it was working closely with unions to resolve the problems.

A 24-hour strike is due to go ahead at the Gloucester business park on Friday 30 July and this will be followed by a week-long strike from Monday 2 August until Friday 6 August.

Unite said further 24-hour strikes will take place on 9, 27 and 31 August with more planned for September.

Matt Draper, Unite national officer for logistics, said: “No one should have to come to work under the fear of being bullied or enter a workplace that is not safe.

“Sadly UPS has consistently failed to address our members concerns and as a result workers are taking strike action as a last resort to finally get these matters resolved.

“Strike action will cause huge disruption and delays to the parcel service in Gloucester and the surrounding areas, not just on the days of the strikes but throughout the summer.

“There is still time for this dispute to be resolved but UPS needs to come forward with meaningful proposals to resolve the problems that our members are facing in the workplace.”

A UPS spokesman said: “We strive to create a working environment that encourages our people to thrive and our business to succeed.

“We are committed to working closely with unions and our social partners to ensure this is the case.”

He added: “We have taken concrete actions to address the concerns raised and have agreed on a path forward.”