Postal workers will begin voting today on whether to stage a national strike over pay and job cuts. Ballot papers are being sent to 120,000 members of the Communication Workers' Union (CWU) which says that Royal Mail is streamlining the business without full consultation.
The vote comes after a series of local strikes across the country in the past few months which have severely disrupted mail deliveries.
The CWU deputy general secretary, Dave Ward, said that the union was prepared to call off all strike action in return for a guarantee from Royal Mail over job security.
He said: "Without agreement there can be no successful change in Royal Mail. This is a simple message which Royal Mail management needs to take on board.
"Postal workers are striking to defend future services as well as for jobs and modern conditions. Modernisation is crucial to the future success of Royal Mail, but the implementation of change must be agreed and it must bring with it modern pay and conditions.
"Postal workers deserve to be rewarded for change. We want to see a new job security agreement which will help people through this time of change for the company."
A number of direct marketing firms have called for the government to intervene in the dispute which has caused a backlog of 20 million letters and parcels in London alone.
The Royal Mail has argued that it needs to reduce its 121,000 workforce in order to survive as mail volumes continue to fall.
Royal Mail managing director Mark Higson said: "The ballot further underlines the CWU's determination to renege on the existing 2007 agreement on pay and modernisation which the union's leadership signed in the presence of the TUC.
"It beggars belief that CWU chief Dave Ward says today that the disruption caused by the CWU strike is hurting customers yet at the same time calls a national strike ballot to step up the damage they are already inflicting on customers big and small."
The result of the strike ballot will be announced on either 8 or 9 October.