Jim Reeves, from the Communication Workers' Union, says the argument to close 70 Crown Post Offices is flawed because the business is profitable.
He spoke to ITV News Central outside the Kings Heath branch in Birmingham as staff went of strike this morning.
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Police were called to The Shannon Inn in Hawkesley Square in Birmingham around 1.40am.
Environment Secretary Andrea Leadsom announced the government funded scheme to enhance Burton's existing flood defences.
Heavy outbreaks of rain on the way, but it will clear through the evening.