The Post Office has said it will offload the remaining 108 branches it directly owns in order to move to a fully franchised network.
The BBC reports that the Post Office has received interest from potential partners including Tesco and Ryman, as well as sub-postmasters, to take on the loss-making branches.
Around 1,000 staff will be given the choice to move to work for any new owner or take voluntary redundancy, but the Communication Workers Union (CWU), has called for the government to intervene and examine alternative options.
CWU general secretary Dave Ward said: "The Post Office's claim that these community services will be maintained by their failed franchising model is laughable to anyone who has seen their local Post Office services reduced to the back of a shop.
"The sell-off of WH Smith last week shows just how fragile and ill-thought out this model is. This is the full privatisation of the Post Office via the back door."
Subject to government funding, the Post Office will stop running the branches in the Autumn, and a decision on who will take them on will be made in the coming weeks.