National air traffic control bosses are to tell a Northumberland wind farm inquiry that allowing the turbines to be built would be disastrous for the environment.

The three wind farms planned for the Kirkwhelpington area north of Hexham have already met with objections from Tynedale Council, the Ministry of Defence and Newcastle Airport.

While the airport is worried about the impact the turbines would have on radar, the National Air Traffic Services (NATS) have gone a step further.

They have urged Government planning inspectors to kick out the plans because just one turbine in the rural heartland would force flight paths to be changed and increase airport delays.

But their biggest concern is that any change to flight paths will lead to more fuel being needed at a time when the aviation industry is coming under immense criticism by environmental groups for the huge amounts of fuel burnt high up in the atmosphere every day.

In documents put before the public planning inquiry into 59 turbines by three energy companies, NATS bosses have warned the wind farms would indirectly contribute to climate change.

Their evidence states the group is sympathetic to wind farm developments and has an excellent history of co-operating with developers to minimise impact on air traffic control and allow as much development as can be safely handled.

But, crucially, it adds that any one of the developments would force a radical rethink of flight paths - seen by airplane companies as a very expensive option.

In his evidence, NATS manager Douglas Ross Maclean said: "In our considerable experience these developments would have a major detrimental impact on [air traffic] operations."

They believe just one turbine would produce clutter on radar essential for airport safety.

Their evidence adds: "The flight may elect to fly around the area of clutter to retain the level of air traffic control service.

"This would have a detrimental effect on fuel burn and increase carbon emissions."

According to NATS, their objection is notable because in 94% of cases, they do not get to the objection stage and resolve issues beforehand.

The British Wind Energy Association said most developers find they can work with air traffic control and do not get to the point where objections are needed.

A spokesman for the energy group said: "As an industry we see the need to work constructively with the authorities on the very small number of cases where wind farm developments might be perceived as problematic to aviation.

"Our members often finance costly consultations and assessments, only to have their projects turned down or blocked without adequate explanations.

"This can be a frustrating and expensive process, while sending the wrong signals on the commitment to build a renewable energy future for Britain."

Another interested party set to attend the planning inquiry is Bill Short, a retired teacher from Kirkwhelpington.

Mr Short has objected to the turbines because, despite being a supporter of wind energy, he has concerns about the effect the proposed turbines would have on the scenic part of Northumberland.

Mr Short has welcomed the air traffic controller's concerns and will himself tell the inquiry that the turbines would do more harm then good. p"They are trying to put turbines that are more suitable to the sea on land," he said.

"It would be ridiculous to have these spoiling views that are essential to the local economy.

"People come here to see the unspoilt views admired by the Romans when they built Hadrian's Wall.

"It would be utterly disastrous to build them here."

A spokeswoman for NATS said their evidence would be presented in the coming months.