They are flying a large orange blimp at a height of 101 metres above the proposed site of the wind farm near Morpeth in a bid to show local people and council planners the likely impact of the installation on the landscape and homes.

The 20ft-long balloon, which is emblazoned with an image of a wind turbine and the word No, is hovering above Todd Hill near the hamlet of Pigdon, where green power company Novera Energy wants to put the four turbines.

It has been brought in by local protest group Put People First to highlight what members see as the overpowering visual impact of the turbines, each of which would be five times the height of the Angel of the North.

County councillors, who are expected to make a decision on the company's planning application in November, have been invited to come along and view the blimp, which will be removed later today after three days in the skies.

It is being flown at the height which the turbines' rotor blades will reach on the local skyline if the scheme is given the green light.

Yesterday Put People First chairman, Tim Weightman, said: "When you see the height the blimp reaches, you get a real feel for the scale of these turbines, and that's without envisaging their long blades and thick masts, plus the fact there will be four of them.

"I think local people have been genuinely shocked to see the height the blimp has reached, and it really brings home what a blight the turbines will be on this beautiful area if planning permission is granted.

"The scale of the turbines is huge and totally out of keeping with the area of outstanding countryside where they will be sited. Because they are so colossal, they will dominate the skyline north of Morpeth and be visible across Northumberland.

"We are also concerned about the impact on wildlife, tourism, house prices and the quality of life of local people. The blimp has caused a lot of interest since it went up on Thursday and we hope county councillors will take the opportunity to come and see it.

"We believe it has been a very worthwhile exercise. Wind turbines must be in the right place but Todd Hill is clearly not that place."

Novera Energy is seeking permission from the county council to erect the four turbines at Todd Hill and a further six at Wingates near the village of Longhorsley.