Churches and cathedrals throughout England could lose thousands of pounds in revenue after a church court ruled against a mobile phone mast because it would “facilitate access to pornography”.

Hundreds of churches have mobile phone antennas in their spires and towers, many through an agreement brokered by the Church of England itself.

Churches can make more than £10,000 a year in rent from mobile phone companies which can be a vital aid to offsetting running costs and repairs. But the mobile phone cash cow is now in danger after an ecclesiastical judge in Chelmsford, Essex, ruled against an application to install a mast in the tower of St Peter and St Paul in Chingford, northeast London.

The parish is to appeal to the Church’s highest court, the Court of Arches, which is the provincial court for the Canterbury Province and sits at St Mary le Bow Church in the City of London. If the Court of Arches upholds the Chelmsford ruling by the diocesan chancellor George Pulman, QC, the Church’s entire policy on the masts could be at risk.

Churches are ideal sites for phone masts because they are often at high level and in the middle of residential areas. Masts on some churches have been disguised as crosses or concealed under stone or gilded statuary.

In 2002 the Church drew up a national agreement between the Archbishops’ Council and the company QS4 which appointed QS4 as its approved aerial designer and installer. More than 50 churches have installed antennas under this agreement but hundreds more are thought to have gained church planning permissions to host aerials.

Local objectors who oppose the aerials on health grounds are often unsuccessful because of the lack of scientific evidence of harmful radiation. But the Chelmsford case has given them a new moral platform from which to fight the masts because of the new 3G or third-generation phones which can access the internet, enable films to be watched and be used for online gambling.

In his judgment Mr Pulman concluded that some of the material to be transmitted “is not consistent with the Christian use of a church”.

He said the original concept of a mobile phone was to enable two people to talk to each other. But now they could be used to download a vast range of obscene images, pornography, pictures of real or simulated child abuse and other material from the internet.

He said he considered it wrong for the Church to facilitate transmission of pornography, even in a slight or modest way. “It is equally wrong for the Church to gain financial advantage, even in a slight or modest way, from the transmission of pornography.”

He found it surprising that many local authorities gave permission for mobile phone masts, given their knowledge through social service departments of the dangers to children from internet pornography.

The Church of England is awaiting the decision from the Court of Arches with concern. A spokesman said : “Whatever the decision, an awful lot of people are going to study it very carefully. If a clear decision is made one way or the other, it is going to impact on the whole process.”