The upgrade plan has prompted local opposition

The energy firm has lodged a formal application to construct an overhead transmission line from Beauly to Denny.

Part of the proposed line runs through the Cairngorms National Park. The firm plans 600 67m-tall pylons, 200 fewer than present, but they would be larger.

A consultation process will start within the next two weeks.

While urging the public to participate, the company has rejected calls to lay cables underground.

It seems that the Scottish Executive's environmental and renewable policies are clashing in the park Roy Tylden-Wright Cairngorms National Park

It claimed burying the 180-mile transmission line would be far more damaging to the environment.

Scottish and Southern Energy said the pylon line was essential to ship power produced by new wind farms and hydro schemes in the Highlands and Islands to customers further south.

Campaign group Cairngorms Revolt Against Pylons has called for a local public inquiry following the application.

The group warned that the move would totally contradict the park's central aims, as well as undermining Scotland's reputation for wild landscapes.

Inquiry call

Spokesman Roy Tylden-Wright said: "If these pylons go through what is supposed to be a protected area, the national park will end up being a national joke."

He said they were convinced that arguments against the alternatives, such as the environmental damage of burying the cables and the high costs involved, were exaggerated.

"It seems that the Scottish Executive's environmental and renewable policies are clashing in the park," he added.