Royal Mail will tomorrow be notified by its largest union that it plans to ballot for strike action, it was confirmed this afternoon.
The Communication Workers' Union (CWU) said "sufficient progress has not been made" in talks with Royal Mail over a number of workplace changes including the scrapping of its final salary pension scheme.
Royal Mail said jobs could only be secured if staff were prepared to adapt to a "more flexible and adaptable" workplace.
A meeting of the CWU postal executive was convened today after the union put a 6 September deadline on talks.
A spokesperson for Royal Mail said it was "very disappointed" with the CWU announcement, re-iterating that there were "no grounds for industrial action".
"We have offered to continue working towards a new pay deal, including aspects of productivity-related pay and opportunities to consider a shorter working week. We are not proposing to change our core terms and conditions or our commitment to a predominantly permanent workforce.
A more flexible and adaptable Royal Mail is the best way to secure as many high quality jobs as possible at the company now and in the future.