A FINAL decision on controversial plans to demolish the building used to test wartime Spitfires is set to be taken next week.

The so-called “Flight Shed” on land near Southampton Airport could be knocked down to make way for new industrial units.

The scheme put forward by Carbide Properties Limited is expected to create “up to 257” permanent full-time jobs.

But more than 47,000 people have signed an online petition objecting to the plans.

It comes as opponents described the site as “the most important” building associated with the Spitfire.

Official documents revealed that because of its history and former aviation use, the Flight Shed is afforded a degree of heritage interest.

It contributed to the testing and assembly of the Spitfire in Southampton, an official report confirmed.

But the document also revealed that Historic England indicated that the building has been “too altered to satisfy the listing criteria”.

Planners said the building was “heavily modified and denuded”.

The Flight Shed and nearby buildings could now be demolished to make way for four industrial units and 112 parking spaces.

A final decision will be taken by the Planning and Rights of Way Panel at Southampton City Council next Tuesday.

In a comment sent to the authority, local historian Michaela Lawler-Levene asked for the plans to be postponed.

Ms Lawler-Levene – who is a trustee of The Spitfire Makers Charitable Trust which launched the online petition – also asked for the petition to be considered.

Writing on behalf of the Trustees of Solent Sky Museum and the Friends of Solent Sky Museum, Alan Jones added: “The Flight Test Sheds are the most important buildings associated with the Spitfire in the World and if Southampton City Council allow these buildings to be demolished it will be a stain on the character of the city.”

Documents published ahead of next week’s meeting confirm that the Flight Shed is “the last surviving structure” of what was once “a prominent group of aerodrome buildings”.

But in the same documents planners also said: “There is no available documentary evidence linking this building specifically to the sole development of one aircraft, such as the Spitfire. It is more likely this structure was a utilitarian building used in the development of many aircraft during its working life. ”

They said that almost all of the building’s original fixtures and fittings have been lost.

“Other than the pitch roof form of the shed itself, there is little, if any, physical evidence within or around the building that can be directly associated with the pre-war or wartime period use of the building,” planners added.

The site was later used by the Ford Transit factory.

The plans are recommended for approval. but civic chiefs have been asked to secure building recording and the installation of panels illustrating the history of the site.

Planning bosses said: “The economic development and employment opportunities weigh in support of the proposal. The replacement industrial units will achieve substantial public benefits in terms of job creation.”