Weston-super-Mare postal workers to strike on Saturday
Some 130 postal workers in Weston-super-Mare are due to walk out in a dispute over deliveries and "un-agreed conduct procedures".
A Communications Workers Union (CWU) spokesman said some of its members were being targeted because their rounds could not be completed on time.
Saturday's walkout will affect the BS22, 23 and 24 postcode areas.
Royal Mail said although it was disappointed at the decision it is confident the issues can be resolved.
'Enough is enough'
"We urge the CWU not to call our people out on strike action which can only hurt our customers and damage our drive to build a strong and sustainable future for Royal Mail," a Royal Mail spokeswoman said.
"Royal Mail is fully committed to the process of trying to resolve concerns of postal workers based in Weston-Super-Mare by continuing to follow the national jointly-agreed framework with the CWU," she added.
The CWU spokesman added it was the first local dispute in Weston for more than 20 years, "suggesting something is radically wrong".
"Postal workers at Weston are being treated completely differently to workers elsewhere in Bristol and the surrounding area," he said.
"They have said 'enough is enough'. The managers responsible for this breakdown in relations seem incapable of admitting their mistakes hence the strike".