The national post strike has entered its second day with more strike action likely to go ahead next week.
The Communication Workers Union (CWU) and the Royal Mail remain at loggerheads, unable to reach a settlement over the modernisation of the service and strike action is planned for three full days next week, starting on Thursday.
CWU deputy general secretary Dave Ward said: “We have today served notice for further strike action. However, these strikes can be avoided.
“We are determined to get an agreement. We want Royal Mail to join us at ACAS and work with us to achieve one.”
Gordon Brown has condemned the strikes and Royal Mail’s managing director Mark Higson said: “Any pretence from the union that they care about customers or about the future of the postal service is now shown to be totally dishonest.”
The continuing deadlock raises fears that the strike will continue into November, a critical month for Christmas shopping, particularly for online retailers.