When the Royal Mail and union leaders resume talks tomorrow they will have only four days to resolve disagreements before the start of a series of all-out strikes that mark a significant escalation in the action.
Depending on which side's figures are to be believed, there are 35 million to 60 million items in an ever-growing backlog. That could rise to 100 million if 121,000 postal workers across the country carry out their threat of co-ordinated walkouts either side of the coming weekend.
The latest round of talks at the TUC ended on Friday, with both sides taking away proposals formed after two weeks of intense discussions. The Communications Workers Union insists it would rather find a resolution to the dispute than hold further strikes. It does not, however, rule out action over the Christmas period.