Council officials have been left red-faced after a series of blunders has forced controversial plans for an office move to be halted for the second time.
East Devon District Council first submitted an application to its own planning committee in September to abandon its former headquarters in Sidmouth and sell off the surrounding parkland for housing and a care home.
But officers were forced to backtrack on proposals to relocate from its historic home at the Knowle when it realised that instead of adding three jobs, the move would lead to the loss of 33.
Now the second attempt has also been withdrawn after the calculated number of workers who would be forced to make a 20-mile round trip to new purpose-built offices in Honiton was also revised upwards from 80 to more than 100.
More embarrassingly for the Conservative authority, the errors were pointed out both times by campaigners, who massed in their thousands earlier this month to oppose the move.
Richard Thurlow, chairman of Save Our Sidmouth (SOS), said the authority was presiding over a "shambles" and predicted as many as 70 jobs could now go.
"This will be the third time the outline planning application will have to be submitted," he added.
"They have made so many mistakes it is scandalous and is costing a fortune."
Opponents had initially hoped English Heritage might grant the offices and surrounding parkland listed status. But conservation experts refused because the edges of the historic site have been eroded by dwellings.
The council's project team pulled its first application before producing a revised statement on the economic impact, reversing a net gain of three jobs to a loss of 33 posts over ten years.
The second application was recommended to be approved by the council's development management committee at a meeting tomorrow .
But on Friday, it was announced that the "data error" had been discovered and the plans postponed. The council said there was "a problem with the raw data" supplied to consultants Peter Brett Associates calculating the number of staff at Knowle who live in Sidmouth.
A spokesman said: "It has since been found that the number is just over 100, taking into account all parts of Sidmouth.
Deputy chief executive Richard Cohen said: "It's much better that this error is spotted and rectified now rather than further down the line. I think it's important that if we make an honest mistake we should say so publicly. That is the only way to retain the public's trust in what we are doing".
A revised report will be available next week, with comments to be made by December 17 and a proposed hearing date of January 8.