The councillors' visit took place on December 16, and bales of straw were used by the developers to show the location of the eight individual turbines proposed.

However, West Ancroft Community Action (WACA) allege one of the bales was 200m away from the position shown on the planning application and photomontages, making it more than 100m further away from the nearest house than proposed.

"This really matters," said Ian Corsie, chairman of WACA. "This particular turbine would have the greatest visual impact and would cause the greatest noise nuisance to nearby residents.

"It is blindingly obvious from E.ON's own photomontages that the bale was in the wrong place. They even got it in the wrong field!

"I don't believe this was a deliberate attempt by E.ON to mislead the planning committee. But, if the position of the straw bale really indicates where E.ON intends to place this turbine, then they must withdraw their present planning application and resubmit it with the correct information and amended photomontages.

"If they have simply made a mistake, they should say so and give councillors the facts. If the company cannot be trusted on simple matters like this, how can one trust other data they provide in their application?" he added.

Mr Corsie said that E.ON staff, who accompanied the councillors on the site visit, failed to notice the error, and it was only local residents who pointed out the mistake to council planning officers following the site visit.

An E.ON spokesperson said: "We have reviewed the methodology used and are satisfied that the bale was positioned at the co-ordinates given in the environmental statement, to within the 50m micro siting distance.

"The accuracy of the GPS device used on the day is +/- 20m and we have subsequently checked the device and found it to be working correctly. We have reported our findings to the local planning officer.

"During the visit, the position of the bales was not relied upon solely for the interpretation and location of the turbines. Due to a number of factors such as the size of the hay bales, weather conditions and terrain on site, not all of the bales could be seen at some of the viewpoints and therefore photomontages were used as the main point of reference during the visit."

A Northumberland County Council spokesperson said: "At the site visit councillors were provided with maps showing the correct locations of where the turbines would be sited and were informed that the bales were not in the correct position. In view of this, no further site visit has been scheduled."

Local residents have also criticised the 'Statement of Community Involvement' that accompanied E.ON's planning application to the council.

It stated: "A poll in the Berwick Advertiser which ran in conjunction with the (West Ancroft) exhibition indicated that nearly 60 per cent of its readership believed the environs of Berwick-upon-Tweed to be a suitable location for wind turbines."

Mr Corsie said: "In fact, this refers to an impromptu website poll on the proposal to locate a single, small, community turbine close to Berwick's Ramparts industrial estate.

"It is ludicrously wrong to claim that nearly 60 per cent of the Berwick Advertiser's 'readership' voted in favour. There was no limit on the number of times an individual could vote and, as a matter of fact, 40 more people voted no than yes."

An E.ON spokesperson told the Advertiser: "It looks like a mistake and we can only apologise for that."

This is not the first time E.ON have been taken to task over alleged errors regarding their West Ancroft scheme.

In July last year, the Advertising Standards Authority upheld two complaints against E.ON for using misleading promotional literature and press advertising for West Ancroft.

Following the secretary of state's decision to reject wind farm applications at Moorsyde and Toft Hill, and approve one for six turbines at Barmoor, Mr Corsie said he was confident that the West Ancroft proposal will be turned down.

He said: "I don't see how councillors on the planning committee could possibly approve this planning application in the light of what the inspector said."

Mr Corsie said he believed issues of noise and landscape impact were equally applicable, if not more so, to the West Ancroft application as the Moorsyde scheme, especially as the proposed turbines at West Ancroft are closer to houses than those proposed, and turned down, at Moorsyde.

He added that WACA had a good case for opposing the West Ancroft scheme due to the fact that it adjoins the Moorsyde site, which was turned down on the basis of the impact of the turbines on the key views of the Cheviots.

These opinions have been echoed by the opposition groups involved with the three other applications, who all see the West Ancroft scheme as having similar issues to the Moorsyde proposal.