Clergy are praying for a road to Damascus change of heart by water companies and Ofwat on a new policy which could land churches with soaring water bills.

Churches are likely to be reclassified as businesses, which could lead to a huge rise in their costs.

The part of the water bill affected by the changes relates to surface water drainage – the disposal of water that runs off roofs and other flat surfaces and needs to be drained away.

On its website, water regulator Ofwat says: “There is no reason why a church or charity should not pay for surface water drainage in the same way as a business as both the church, charity and the business would be making a similar demand on the service.”

The Rural Dean of Epsom Deanery, the Reverend Stuart Thomas is horrified at the proposed changes.

He said: “We just haven’t got the money. It would mean that money would go into less appropriate things like paying the salary of water bosses rather than helping those in need.

“More and more of the money collected from congregations will be going into paying utility bills.”

He estimated that some churches could see a £3,000 rise in their costs.

A petition has been launched by the Methodist church on the Government website calling for a U-turn on the policy, which has already been implemented in four areas of the UK and could go nationwide in two years.

Mr Thomas said: “A lot of these things are hidden away and you don’t know they are there until it is too late to do anything. My business is merely to inform people, not to pressure them into signing.”

In a statement, Thames Water said: “Currently charges are dependent on the rateable value of the property, or by the size of the water meter. Ofwat have instructed us to consider changing this so that charges are based on the total area of the property drained.

“This is a fairer way of charging for surface water drainage and is likely to be implemented by 2010.”