An iconic Grade I-listed building that is the only one left in existence in Wales has been damaged since work was postponed last month, a councillor has claimed.

Significant conservation work on the Old Market Hall in Llanidloes has been put on hold by Powys County Council until later this year after more issues were found.

Councillor Alan Bennett described the situation as a “shambles” that will be in Llanidloes “for eternity”.

Llanidloes Town Council, which owns the building, agreed to write a letter to Cadw to share their “disappointment” at how their meeting with Powys County Council representatives about repairs to the black and white building in the town centre came “with no suggestions to protect this protected building”.

County councillor Gareth Morgan said: “The situation is causing so much concern and controversy in the community.

“We were told there was no money to do anything. It killed the meeting stone dead. I was very disappointed no options were brought forward."

Cllr Morgan added: “All heavy good vehicles should be barred from north of Llanidloes. They found all sorts of reasons how that was impractical.”

Councillor Margot Jones said she went home “in a state of despair”, while Llanidloes Mayor Cllr Jamie Jones said the meeting was “very disappointing” and “awful with suggestions”.

Meanwhile, Councillor John Hughes described the outcome of the meeting on March 24 as “pathetic”.

“We were disappointed they didn’t come up with options,” he said. “They should give us a lot of options instead they were waiting for us to do their job for them. It was amazing.”

Councillor Alan Bennett accused the county council of ignoring concerns raised by the town council.

“The Old Market Hall was there long before the bypass was created,” Cllr Bennett said. “The problem is turning left for the Maesyllan estate with their Sat Navs.

“Trailers are swinging around and hitting it again. Lorries have caused damage already since they’ve been there. They seem that they don’t want to listen.”

The council agreed to send a letter to Cadw explaining their discontent about “how ineffective the meeting was and disappointed the highway authority came with no suggestions to protect this protected building”.

A spokesperson for Powys County Council said: “Officers from council services including corporate property, built heritage and highways met with Llanidloes Town Council to discuss the Old Market Hall in Llanidloes and how to protect this important building.

“The purpose of the meeting was to get the views of the town council so that a scheme can be developed that would then protect this iconic building for future generations.”

Powys County Council postponed the second phase of work on The Old Market Hall until the Autumn to “minimise the disruption through the tourist season”.