BAT conservation is costing churches thousands of pounds and is unsustainable, a delegation for the Church of England, led by Second Church Estates Commissioner, Sir Tony Baldry MP, has warned.

The delegation urged the Environment Minister, Richard Benyon, to come forward urgently with ways to help churches deal more effectively with bats.

Leaving interpretation of the law on bat conservation largely to the Bat Conservation Trust (BCT) is bringing the European Habitats Directive into disrepute to the detriment of endangered species more generally, they said.

Up to 6400 churches in England are thought to be used by bats, which are a protected species, and Natural England, the Government's wildlife adviser, has to be consulted in advance of any work that might disturb them.

The Bishop of Norwich, the Rt Revd Graham James, said that churches were being treated like "uninhabited barns".

Annie Sloman, who chairs the Church Buildings Council, accused the Government of "over-delegation" to the BCT. The Church Buildings Council has been working with Natural England on research projects for more than a year to try to find a way forward that costs churches less.

Having bats in churches could raise costs substantially, the delegation said. The cost of replacing one small piece of a leaded window increased from £5, using plain glass, to £140 when fitting a lead "bat flap" - four weeks' collection in the rural parish church of Wiggenhall St Germans, in Norfolk.

The Archdeacon of Cleveland, the Ven. Paul Ferguson, highlighted the problem for one of his parishes, saying that "£29,000 has been spent so far by the congregation of St Hilda's, Ellerburn, on two bat problems, and, although a licence to do something is now promised, it is by no means certain. Meanwhile, the cost in financial and human terms to those who worship there continues."

Sir Tony said that he was equally frustrated by the lack of progress.

The BCT said, however, that it was "dismayed" by the comments of the C of E's delegation.

Its CEO, Julia Hanmer, said: "As both a committed conservationist and Christian, I am sad to see the Church of England publishing inaccurate stories and reviving old misunderstandings about bats. I can't see how this promotes the Church of England's mission, which includes 'striving to safeguard the integrity of creation and sustaining and renewing the life of the earth'.

"The Bat Conservation Trust recognises that, in some cases, the presence of bats can be very problematic for those who use or maintain church buildings, and that integrating the protection of bats into the care of church buildings can be challenging, especially for small or under-resourced communities. It is often possible to find solutions to address or alleviate such problems, given the right support, and the willingness to find a solution that helps both people and bats."