Angry campaigners say district chiefs are ‘flagrantly overstating’ savings in justifying their relocation from Knowle – and argue public accountability is essential before any decision is made.

Save Our Sidmouth chairman Richard Thurlow warned there was ‘every prospect’ of a judicial review if East Devon District Council (EDDC) goes ahead with the move, which assumes an energy price increase three times what the Government is predicting.

The authority expects to save £5.5million in running costs by moving its staff to a purpose-built property at Honiton’s Heathpark and existing offices at Exmouth Town Hall. It hopes to sell its ‘unfit-for-purpose’ Knowle HQ and borrow £5million to keep the relocation cost neutral.

Mr Thurlow said: “We are very unhappy with the figures used by EDDC – they are vastly in excess of those suggested by official bodies, and EDDC has provided no real justification for their use.

“In our opinion, it will be extremely dangerous to proceed on a project whose only financial saving is via hypothetical energy savings over a 20-year period.”

EDDC figures predict a 10 per cent increase in the cost of gas over the next decade, but expert forecasts put it closer to three per cent – leaving deputy chief executive Richard Cohen ‘out on a limb’.

Mr Thurlow added: “They have not adopted Department of Energy and Climate Change or any other official figures, but used their own, with absolutely no justification.

“We believe that it is essential for EDDC public accountability that the full set of costs and savings for the relocation are available to the public, before any final decisions are made.”

He said there would indeed be some energy cost savings from the move, but the council was duty-bound to release any non-commercially sensitive data to justify it.

Town council candidate Marc Kilsbie added to the calls for transparency, saying: “We paid for the body of work to be done – why aren’t we allowed to view what we have paid for?

“Why have we paid £6,800 [in legal fees at a tribunal] to prevent us from seeing it?”

Responding to the direct question, an EDDC spokesman said: “Full council agreed on December 17 that no final decision will be taken on relocation until there has been a thorough examination of the figures underpinning the project by the council’s audit and governance committee, overview and scrutiny committee and internal audit and external auditors.”