The Post Office today attempted to play down the impact of a strike at its branches today, saying the industrial action would only affect a tiny portion of its outlets.
Workers at 114 branches still run by the Post Office walked out today for 24-hours having voted almost unanimously for industrial action in April.
The Communication Workers Union (CWU) said members were angry over a pay freeze in 2021-22 and a 2% rise for the following year, which the Union described as insulting.
The CWU said the pay offer was not nearly enough to keep up with rapid increases in inflation recently.
CWU official Andy Furey said: "The current offer of a mere 2% pay rise over two years is nothing short of an insult to these key workers who provided exemplary services to this nation during the pandemic.
"As the cost-of-living crisis mounts, working people across the country are facing stark realities.
"This isn't any less true of Post Office employees, who deserve far better than the degrading offer currently on the table.”
The Post Office said the vast majority of its 11,000 branches would be open as usual.
It said in a statement: "There are 114 branches - typically in city centres - across the UK that are directly managed by Post Office.
"Posters are displayed which show where the nearest alternative branches are located. Customers can also find more information at postoffice.co.uk/branch-finder."
The Post Office is a private company run by the government.
UK-listed Royal Mail, the delivery part of the UK postal service, meanwhile is also facing industrial action over plans to fire and re-hire 1,000 managers.
Reports at weekend said Royal Mail staff will also hold a strike ballot this month over plans to make them work on Sundays.
Royal Mail chief executive Simon Thompson is set to hold talks with the union this week in a bid to avoid industrial action.