St Mary’s Parochial Church Council is to appeal against the refusal of planning permission for an extension at the Devizes church.

Wiltshire Council’s Eastern area planning committee narrowly agreed with its planning officers to turn down a proposal for a curved glazed cloister extension at a meeting in October.

Both the council and English Heritage opposed the extension because they said it was too big and would harm the setting of St Mary’s Church, which is Grade I listed.

St Mary’s PCC has been working on the plans to redevelop the 12th century building for five years to ensure its viability and had widespread community support. In addition to the extension, the plans involve using the inside of the church for performances which could be attended by up to 260 people.

The Rev Canon Paul Richardson, rector of St Mary’s, said that without the extension the church would close.

St Mary’s representatives met Wiltshire Council officers and English Heritage just before Christmas to discuss what alternatives were acceptable in planning terms but without success.

Mr Richardson said: “Regrettably there appears to be no common ground on which we can agree without compromising the vision we have to regenerate the building for future generations, so we will be making an appeal.”

He said English Heritage and Wiltshire Council had suggested removing the vestry and adjacent yew tree, building out from the east end and bringing toilets and offices inside the church.

Mr Richardson said: “We believe these proposals would have a negative impact on the medieval interior and seriously affect the viability of the business plan. We think our scheme is superior in terms of protecting the church and have less impact on the setting.”

The St Mary’s Future Group will hold a public meeting in the church on January 23 at 7.30pm.