Campaigners have cried "foul" after planners approved the extension of a mobile phone mast at Sarum Road, Winchester.

It can now be increased from 15 to 20 metres in height.

Anti-mast campaigner, Karen Barratt, said Winchester City Council should not have relied solely on technical data supplied by the applicant, Hutchison 3G.

"Listening to the so-called debate in the planning meeting, where there was no independent technical advice available, was very much a case of the blind leading the blind," she said.

She is concerned about possible health risks posed by radiation from the extended mast.

The structure is around 500 metres from Western Primary School, which Mrs Barratt feels is too close for comfort.

She has spent the last four years fighting plans by Orange to build a 12-metre mast 150 metres from the school, in Byron Avenue, where she lives.

Geoff Bennetts represents Fulflood on the city council and chairs the sub-committee that deals with phone masts.

He supported Hutchison's application when it went before the council. He said the extra height, while increasing the mast's coverage, would not increase its power output.

He added that he did not believe the mast posed any health risks to Western Primary School, where he is a governor.

A council spokesman added that they often used technical data supplied by mobile phone companies.

"We've found in the past that the mast operators are open and honest with us."

Because the companies risked future data being discredited if any of it was found to be false, it was in their interests to provide accurate research.