A test-case appeal is to be heard in the Purbecks, Dorset, over a horse shelter.

Councillors backed enforcement action over the mobile stable late last year after hearing that planners feared an uncontrolled rash of similar shed-style buildings around the beauty-spot rich district.

The wooden shelter was put up in a field at Woolgarston, between Corfe Castle and Swanage. Its owner told planners that the makers claimed it did not need planning permission because the structure was not attached to the ground.

But planners argued that the stabling was a material change of use of land, and won backing from councillors to take enforcement action.

An appeal against that action is now to be decided at a public inquiry. Planner Alan Davies told councillors: “The law on this is not clear cut.”

He said that if the council’s view failed to prevail at an appeal, there would be widespread ramifications, adding: “We could have these sheds popping up all over Purbeck without control.

“That would be very, very unfortunate in an area of outstanding natural beauty, heritage coast and green belt. It could completely change the character of the area.”