Thousands of Post Office workers are to stage a 24-hour strike in disputes over branch closures, jobs and pensions.
Members of the Communication Workers Union will walk out on September 15 after voting overwhelmingly for industrial action.
The union warned of an ongoing dispute over jobs, services and pensions, saying the Post Office was at a crisis point.
Dave Ward, general secretary of the CWU said: "The Post Office is relentlessly pursuing a programme of cuts that will mean a further 2,000 job losses, staff being left tens of thousands of pounds worse off in retirement and the privatisation of its flagship branches.
"The Post Office is at crisis point and the Government has to step in.
"We are making a simple demand. The Government needs to pause the cuts, convene a summit of key stakeholders in the industry and work out a strategy that gives employees and the public confidence that the Post Office has a future.
"The Post Office has pointed to the bottom line in making these cuts, but it cannot pretend that using public money to pay off staff so they can be replaced with part-time jobs on the minimum wage is a success story or that closing down its flagship branches is a defence of the service.
"The Post Office has got to get out of the cycle of closures, job losses and attacks on staff terms and conditions. It needs a serious plan to grow revenues in areas like financial services.
"Other countries have brought in hugely successful Post Banks. There is no reason why our Post Office should be the world leader in managed decline."
CWU deputy general secretary Terry Pullinger said: "We are announcing the first day of industrial action and if the Post Office is not prepared to change its position it faces an ongoing dispute with our members.
"This is a major campaign to defend the very future of the Post Office and force Government, as the owner, to live up to its responsibility and past promises and sit down with all stakeholders to agree a positive vision for the future rather than one that celebrates structural decline.
"The Post Office is offering staff thousands of pounds not to go on strike and is threatening to make CWU reps redundant.
"It is incredible that a publicly owned company is behaving this way and the Government has got to make clear that this is completely unacceptable."
"The proposals from the Post Office to close its pension scheme have no justification.
"With a surplus of over £130 million the Post Office has the best funded pension scheme in the country.
"In closing it down the Post Office is stealing the money our members have built up over many years of service and backtracking on its promises to keep the scheme open."