A series of protests have been held across England and Wales against plans to close post offices and transfer services to WH Smith stores.
Several Post Offices are to be relocated to WH Smith stores
Communication Workers Union (CWU) members gathered outside six stores to highlight the 124 jobs it says will be lost under the transfer.
They handed out leaflets urging shoppers to boycott the retailer.
A WH Smith spokeswoman said it was "disappointing", because the deal would ensure the services remained available.
"Our plan with the Post Office, we think, is a good one. It will certainly save Post Offices that would otherwise close.
"It's disappointing that they're encouraging people not to shop in our stores as Saturdays are our busiest days," she said, adding that the protests were unlikely to have much impact on turnover.
The protests were held in Swansea, Slough, Shrewsbury, Altrincham, Ashton-under-Lyne and Hammersmith in west London.
Post Office director Byron Roberts said it made "no sense whatsoever" to direct protests at WH Smith.
The union said its members who lost their jobs would be replaced by inexperienced employees.
Union organiser Chris Roach said the public were "very, very supportive" of the protest outside the Swansea WH Smith. "A good many shoppers said they wouldn't use WH Smith on this particular day."
High street services
CWU national officer Andy Furey criticised the Post Office for its treatment of staff.
"Collectively, thousands of years of experience are being axed and scant provision for new services provided. Without our members, we believe WH Smith cannot begin to replicate the standard of services the public expects from the post office.
"We are now encouraging local residents to boycott WH Smith to force it to reverse its decisions to play a part in this desecration of the Post Office network."
The union is already balloting hundreds of workers for industrial action over the move.
But Mr Roberts said: "The partnership between Post Office Ltd and WH Smith is all about keeping post office branches open, providing all current services, in new premises and with improved facilities.
"Almost all Post Office branches are run in partnership with independent, privately-owned businesses.
"The small number of branches run directly by Post Office Ltd, in high street locations, lose £50m every year."