Thousands of postal workers will go on strike this Friday, threatening widespread disruption to mail services.

Some 12,000 staff are expected to take part in walk-outs organised across Britain by the Communication Workers Union in protest over job cuts and workloads.

The union said that the activity could escalate to a national strike and accused Royal Mail of “sulking” since plans to part-privatise the group were shelved by Lord Mandelson, the Business Secretary.

Royal Mail claim that 90 per cent of offices would not be affected. The union and Royal Mail are accusing each other of abandoning the pay and modernisation programme agreed in 2007.

Dave Ward, deputy general secretary of the CWU, said: “There are serious and growing problems in the postal sector which urgently need resolving. We have renewed our offer of a three-month no-strike deal to Royal Mail in return for meaningful talks over modernisation.

“The current cuts, bullying managers and ever increasing workloads on a shrinking workforce cannot continue. Pressure and stress is at breaking point for postal workers so we urgently need a fresh start for a modern Royal Mail.”

Workers in London went on strike for three days last week. This strike includes London, as well as staff in Edinburgh, Bristol, Darlington, Stoke, Plymouth, Leamington Spa, Norfolk and Essex.

Mr Ward added: “Without progress this could effectively turn into a national strike.”

Last week it emerged that the chairman of Royal Mail’s pension trustees is thought to be considering closing its final salary scheme.

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