The Royal Mail is planning to shut a sorting office in a Powys town which could result in a "major decline" in the service, a councillor claims.
The work and eight jobs in Llanidloes will switch to Newtown under the cost cutting proposals.
But county councillor Gareth Morgan said the area's delivery service would suffer.
Royal Mail said it was carrying out a feasibility study, adding that there would be no compulsory redundancies.
In recent months, Royal Mail has shut a sorting office in Mountain Ash and moved the work to Aberdare in Rhondda Cynon Taf.
Another office in Llandovery is closing on 7 March and the post will be sorted in nearby Llandeilo, Carmarthenshire.
Mr Morgan, a former mayor of Llanidloes, said: "Without any public announcement, let alone consultation it has reached my ears that Royal Mail Limited is to close the Llanidloes postal sorting office, potentially putting a number of jobs at risk in Llanidloes.
"All postal sorting will in future be done at Newtown from which distribution will take place. If any of our dedicated and excellent team of postmen are to run any chance of retaining their jobs they will have to commute to Newtown.
"Llanidloes has enjoyed a sorting office since the postal service was first set up, and it is scandalous that the town and the valued staff of postmen should be treated in this way."
Mr Morgan said the consequences of closing the office would "result in a major decline in the service that we have enjoyed over the years".
A Royal Mail spokesman said it did not have to consult with officials in Llanidloes because it was a business decision to close the sorting office.
"As a commercial business, operating in a market that is open to competition from other postal operators, Royal Mail is always looking at ways to reduce its costs and improve efficiency, with minimal impact on its customers," the spokesman added.
"Whenever a delivery office move goes ahead, we would always offer our customers alternative means of receiving undelivered items of mail, including re-delivery to the addressee, to another local address specified by the customer, or to arrange collection from a nearby Post Office branch."