Union leaders have announced fresh postal strike dates after branding Royal Mail "completely out of control".
Royal Mail employees will stay away from work from Friday 5 October to Tuesday 9 October - five days of non-delivery for customers.
There will then be consecutive daily strikes by different departments from 15 October until the dispute over pay and post office closures is resolved, according to the Communication Workers Union (CWU).
Dave Ward, CWU deputy general secretary, said: "The workers have had enough of Royal Mail messing them around. We're not going to tolerate an employer that ignores its workforce, ignores the union and ignores its customers.
"Strikes are a proportionate response to an employer that is completely out of control. Rather than running the business, Royal Mail's actions demonstrate it is intent on destroying it."
The CWU is still trying to secure a pay deal for the year commencing 1 April this year. It says Royal Mail's offer is linked to unacceptable propositions on flexibility and decreased pensions benefits.