DETERMINED residents are battling a telecommunications giant's plans to extend the size of a phone mast in Cross Keys.

They have written letters to the National Assembly before a planning appeal, in a bid to stop Vodafone replacing a 15 metre metropole mast and three antennae with a mast of similar height but with two extra antennae.

Vodafone submitted the planning application to Caerphilly council earlier this year.

People living in the area objected to the move on the grounds that the mast, on land off Risca Tyres in Medart Place, was within a 50m radius of Waunfawr primary school, Coleg Gwent's Cross Keys campus and a residential home for the elderly, as well as houses.

They said the extra antennae could be detrimental to the health of people living there. The claim is rejected by Vodafone.

The plans were turned down by the council but Vodafone appealed against that decision. The planning appeal will be decided by a Welsh Assembly inspector, by means of submitted written statements.

Residents had until Friday to put in their responses. Lynne Rees, secretary of Cross Keys and Pontywaun Residents Association, said she took the letters to the Assembly in person last week.

She said: "The proposed mast would be detrimental to a residential amenity because of perceptions by local people of the effect it could have on their health.

"If people use mobile phones then that is their choice. But if they put the mast close to where we live, we haven't got a choice. People are also worried about the potential devaluation of their properties."

Cross keys councillor Michael Gray said that people understood masts were essential for communication, but said they should be sited on the mountainside rather than in a residential area.

A spokeswoman for Vodafone said earlier this year that all the company's installations complied with very stringent international guidelines, designed to protect the public.

Those guidelines had the formal backing of world health organisations.