A union leader is opposing a controversial mast for a new police walkie-talkie system which is planned near a factory in mid Wales.
People are opposed to the planned tetra mast in Llanidloes
The Transport and General Workers' Union's regional organiser Howard Clark, claimed that the 15-metre Tetra tower could pose a threat to people's health in Llanidloes.
Mr Clark added that more than 20 members of the T&GWU working for Quality Tools and Engineering, which plans to rent land near the proposed mast site, could be affected by the development.
However, the National Radiological Protection Board (NRPB) says there is no evidence Tetra is dangerous.
Mr Clark said his members were not opposed to the emergency services' communication facility, but he claimed little was known about the effect on people from Tetra masts.
Tetra is a new hi-tech police secure communications system. It is in the process of being rolled out across England and Wales with 3,200 masts - 300 of them in Wales.
"The mast is being erected near Quality Tools and Engineering for purely economic reasons," said Mr Clark, who was speaking before a public meeting on Thursday night to discuss the issue.
"We're not against any improvement to the emergency services' communications system, but we seem to know very little about the effects such a development could have on people living or working near the mast.
"I'm not convinced there'll be any long-term benefit to the residents living nearby or to the factory workers by erecting this Tetra mast."
But Nigel Hellawell, managing director of Quality Tools and Engineering, said he was in favour of the mast.
"There are people against the mast, but I have no problem with it," he added. "We were approached by the company and it asked if it could rent some land."
Claire Parker, on behalf of MM O2 Airwave, the company developing Tetra, said the mast was not for the public network, but it was for public safety.
"The Tetra mast is specific technology for the emergency services," said Ms Parker.
"The police have specified they need a new communications system and we locate them in certain areas and there are very good reasons for that such as power supply. There's no evidence there is a risk to health."
A spokesman for the Llanidloes Tetra Mast Action Group said a petition had been circulated in the town against the development on the Maes y Llan industrial estate.
"We not convinced by the arguments that Tetra masts don't have an effect on people's health," he said.