The Communication Workers Union has launched another week of postal strike following the biggest week of industrial action that saw 20,000 Royal Mail workers participate.
Millions of letters and parcels are expected to be delayed across the country. London was particularly hit hard on Friday August 28 and Saturday August 29 with 4,100 and 7,500 workers participating on respective days.
The row over pay, job cuts and working condition between the CWU and Royal Mail managers have lead to a series of strikes that have disrupted mail delivery and collection.
The union also opposes plans for part privatisation of Royal Mail that is backed by the government.
Royal Mail has so far refused to negotiate with the union. The union, on the other hand, is urging Royal Mail to enter into negotiations to diffuse the situation that has produced several postal strikes over the past few months.
The latest series of week long strike began last Friday and will end on Thursday September 3.
Commenting on the recent developments, Dave Ward, CWU deputy general secretary and head of the postal division in CWU said: "Royal Mail needs to accept that there has been a big breakdown in trust between staff and management.
"The way to resolve this and get the modernisation programme back on track is to have serious negotiations with the CWU to reach a fair and workable agreement.
"We welcome the planned meetings with Royal Mail next week, however until there is a material difference for our members we will not be in a position to call off strike action."
"While Royal Mail has today boasted about service targets we advise the public to treat this with caution because there is a live investigation being undertaken by Postcomm which may well call the validity of these figures into question."
Both parties accuse each other of blocking modernisation within Royal Mail and the government has refused to put pressure on Royal Mail to enter into negotiations with the union.
The union has called for a national ballot that begins on September 9 and closes on 23 September. If the union members vote in favour of a national strike, it could lead to 130,000 Royal Mail postal workers taking part in the walkout.