A decision by Shaftesbury Town Council on buying two significant properties in the town, unexpectedly delayed at a special meeting of the council on 27 November after councillors raised a number of concerns about the costs, is now to be made on 5 December.

The council is debating whether or not to buy the redundant former supermarket in Bell Street and a natural wilderness on the site of an old quarry on the edge of town for an estimated £1.2 million.

Development costs of the former Budgens supermarket building alone are expected to increase overall costs to more than £2 million.

The town council went into secret session to discuss the costs last week after some 60 members of the public had turned up to lobby in support of both plans. But several councillors voiced a number of serious doubts about the two schemes before the public were excluded.

Leading the concerns, Councillor Andy Perkins said the proposal to buy the supermarket posed ‘a massive risk’ to the council because the council did not yet know for certain where exactly the money was going to come from to buy it, what exactly it was going to do with the site after it had bought it, how it could be made to work financially, and what effect it would have on council tax levels in future.

He said if the scheme did not work it would become ‘a millstone around our necks’ that would weigh the council down ‘for years’.

Councillor Tim Cook asked how certain the council were that it would get its money back if the the plan went ‘pear-shaped’ and Councillor Mark Jackson wanted to know how confident the team preparing the bid were that they would get the public funding for it in the first place.

The decision to defer a decision was taken to give the bid team, led by the council’s business manager Brie Logan supported by former senior North Dorset manager Hilary Ritchie, more time to come up with clearer answers.

Final bids for the supermarket have to be in by 7 December and the auction for the land known as The Wilderness is on 14 December.