The developers of the proposed 136-mile Beauly to Denny power line have disguised the true impact of the 600 giant pylons in visual evidence presented to the public inquiry, according to critics.

They claim photographs in the environmental statement presented by Scottish and Southern Energy and Scottish Power were comparable to an estate agent's most flattering portrait of a less than desirable property.

The inquiry holds its first local session in Inverness today. Ahead of the session, the Beauly to Denny Landscape Group, which embraces six organisations opposed to the line, staged a presentation yesterday to give the public a chance to see how obvious the pylons would be.

The group had commissioned Stuart Young, a Caithness-based construction consultant who has specialised in scrutinising windfarm applications, to examine the developers' visual representations.

He said: "I looked at four of the 25 images presented in the public statement and cast doubt on them all." This led him to question the others.

One of the images he scrutinised was a photo-montage looking southwards down the A9 in Glen Truim. "That's what first rang a bell. It was taken from the A9 where the pylon line would come across from Fort Augustus and down towards Drumochter.

"The first thing that strikes you in this image is that there is only one pylon showing. The following day I had a look at it and discovered that at that point there would be virtually no view of the pylons. But less than 100 yards away there is a parking place where you would be able to see 12 or 13. "Whoever took the picture must have left his car and walked to a spot where he wouldn't see anything.

"I am not trying to say my pictures are better than yours. What I am trying to say is that you could have shown that in your picture but you chose not to. This view was available but it wasn't used."

He compared it to Nelson seeing no ships. "Cynically that's what happened here."

Mr Young also scrutinised a photo-montage of the east end of Loch Laggan. The picture had not been taken from where they said. It had been cut to exclude two pylons.

He had also been confused by the absence of an angle pylon which is bigger than others because it is where the line comes up and turns in a new direction.

"They forgot to put it in. It is not there. But I came across it quite by accident on the electronic version (of the environmental impact assessment) after I zoomed it up to 300%. It is not visible in normal magnification. It was also the wrong height and in the wrong place."

In conclusion Mr Young said: "These images are technically correct, but not representative. Each photograph has been deliberately chosen."

The developers are making no comment during the public inquiry.