Now, campaigners against the controversial proposal in the Swansea Valley say they will prosecute npower renewables under the Wildlife and Countryside Act if the farm goes ahead and Red Kites - dubbed Wales' National Bird - are chopped up in turbine blades.

The soaring hawks were so prevalent centuries ago, Shakespeare called London "a city of Red Kites and crows".

But until very recently, the Red Kite was on the brink of extinction.

By the turn of the 20th century, only a handful remained in the UK, having taken refuge in the isolated Cambrian Mountains of Mid Wales.

With the Red Kite about to disappear, every bird was monitored and nests in Wales were even guarded from illegal egg collectors by teams of kukri -wielding Gurkha soldiers.

The Red Kite programme became one of the conservation success stories of the last century with latest estimates putting the number of breeding Red Kite pairs in Mid Wales at more than 250.

As a tribute to its survival skills, the Red Kite was voted Bird of the Century in 1999 and a year later, at the turn of the millennium, the Red Kite was also labelled Wales' National Bird.

But Ioan Richard, an ex-teacher and Swansea councillor who opposes npower's plan to site wind turbines on Mynydd y Gwair common, north of the city, said: "It could be a Red Kite slaughter because these birds are regulars in this area.

"It's unusual for a wind farm company to admit significant risk to birds, especially the emblematic Red Kite in its Welsh heartland, but this is just what they have done.

"It's illegal to kill the Red Kite so people plan to prosecute if this wind farm is ever agreed and npower have gone as far to have signalled Red Kite deaths beforehand. How blatant can you get?"

In its planning submission to Swansea Council, npower say: "The only species judged to be at significant risk of collision with the operational wind turbines are Red Kite, kestrel and Golden Plover.

"At the level of collision predicted, the effects are likely to be only significant in the context of Red Kite and Kestrel both of which could see some depletion of the immediate local population and to a lesser extent, buzzard."

Tanya Davies, development manager for Wales, at npower renewables, said: "The environmental statement is an assessment of the potential environmental effects of the proposed Mynydd y Gwair Wind Farm, and is a statutory requirement of the planning process.

"Statutory bodies, including the Countryside Council for Wales and the Royal Society for the Protection of Birds (RSPB) Cymru, have been consulted as part of the planning process by the City and County of Swansea Council. RSPB Cymru formally responded to the application and have raised no objections to the proposal subject to planning conditions relating to any potential risk to Red Kites."

An RSPB spokeswoman said: "The RSPB believes the development of any form of energy, renewable or otherwise, must not compromise nature conservation objectives.

"In order to do this, we assess all wind farm applications in Wales to judge whether they will have a significant impact on birds of conservation concern.

"We have assessed the Mynydd Y Gwair application and while there is a low risk of collision to Red Kites in the immediate area, we have asked for certain conditions to further reduce this to be included in a planning permission."

Ornithologist Tony Cross, of the Wales Kite Trust, said: "We remain impartial with regard to wind-energy development per se but we are obviously concerned at any development which has the potential to significantly affect the Welsh Red Kite population."