Postal workers have begun clearing a huge backlog of millions of items of mail as the latest wave of strikes ended, with little sign of any fresh moves to break a deadlocked row over jobs, pay and modernisation.
Two 24-hour walkouts on Thursday and Friday led to 30 million letters being delayed, about 40% of an average daily postbag, although union leaders maintained that the figure was much higher.
Royal Mail said there had been no problems today with the return to work, with deliveries resuming across the country.
But fresh strikes will be held for three days from next Thursday unless the company and the Communication Workers Union can resolve the dispute in the coming days.
Royal Mail chief executive Adam Crozier will give his first interview since the strikes started when he appears on BBC TV's Andrew Marr show on Sunday.
Meanwhile, Unite confirmed it had written to its 10,000 members who work as managers at the Royal Mail, stressing the union's support for the CWU.
The letter, emailed to members last week, said: "It is our wish to give CWU all possible support, within the law, to help ensure a satisfactory settlement to the dispute.
"We would ask you to ensure that you undertake no work beyond your normal duties which would assist management in its efforts to undermine legitimate industrial action."
The managing director of Royal Mail, Mark Higson, told the BBC: "We are really calling on the CWU to accept the agreement that they looked at last Tuesday night and to join with us in signing that agreement, which will mean that any strikes are unnecessary."
A Royal Mail spokesman said: "The issue for us is to make sure we clear the backlog as quickly as possible."