Kevin Gilliland, network and sales director at the Post Office, said the Communication Workers Union's (CWU) decision to strike will "cause disruption to customers."
The CWU are calling for an above-inflation pay agreement when last year our overall performance was a loss of £116 million.
We must reverse this loss of public money. Strike action can only cost our people money, cause disruption to customers and threaten our plans to turn the business around and keep our branches on high streets and in city centres across the UK.
The CWU's call for its members to stop proactively introducing financial services to customers is extremely irresponsible.
– Kevin Gilliland, network and sales director at the Post Office
The Communication Workers Union deputy general secretary Dave Ward said post workers were striking today due to the "reckless attitude of the post office".
If the Post Office thinks this dispute will simply fade away they are sadly mistaken. Our members are fiercely opposed to the company's plans to close and franchise offices, slash jobs and impose a pay freeze.
The company's plans are to downgrade the network, reduce services to local communities and hit jobs in the network. There is no mandate for this course of action and customers across the country are appalled at the reckless attitude of the post office towards these public services.
Mr Ward added that the strike, which will affect up to 4,000 staff in 372 offices today, could carry on into the Christmas period.
The strike and the continuing sales ban activity will continue into the Christmas period unless management see sense and negotiate a fair deal for Crown office staff.