They are worried that there could be health risks from the mast, which is sited just 30 metres away from classrooms in Russell Lower School, Ampthill.

One transmitter on a mast erected on a tower belonging to Bedfordshire Fire Service is already in place, but is not yet active.

A total of three mobile telephone companies are reported to be in negotiations with the service about operating transmitters from the tower which overlooks the school, and is close to gardens and houses.

'Guinea pigs'

Judy Bramwell, head teacher of the school which has 220 pupils aged between four and nine, said: "A lot of parents have expressed their concerns about the risks these aerials may pose to their children.

Parents are worried about their children's health

"My concern is that until we know for certain, we should err on the side of caution."

She said the school's governing body had written to their local councillors in Mid-Bedfordshire District Council and the local Conservative MP Jonathan Sayeed expressing their concerns.

Parents are also organising their own campaign against the mast, and are holding a public meeting on Wednesday evening to rally support.

Joanne Goddard, who is co-ordinating the parents' protest, said: "Nobody can tell me for certain that these masts are safe. The children's bodies are still developing, and as a parent I am not prepared to let my child be a guinea pig."

Mrs Goddard, who also lives near the school, is organising a petition calling on the fire service not to let the transmitters operate from the tower.

"I don't want any masts to go up within the next 10 years, unless there can be an absolute guarantee that they are safe."

'Conforms to safety requirements'

Another parent, Mark Wallace-Bell, whose garden backs onto the fire station, said: "We are very concerned about the health risks.

"It has not been proven, but there are fears that mobile systems emit microwave radiation that causes disorientation, short-term memory loss and sleeping disorders."

In Australia, New Zealand, Sweden, Italy and parts of the USA, mobile phone masts cannot be sited near schools.

But a spokesperson for Bedfordshire Fire and Rescue Service said: "This mast will bring in £6,640 a year for the service.

"We are assured by our site management consultants, who are experts in this field of technology, that this aerial conforms to all the safety requirements of the National Radiological Protection Board."