In an unprecedented piece for Tuesday's Radio Times, the Prince wrote rare breeds of farm animals which were part of the UK's "cultural heritage" were under threat.

Charles laid much of the blame at the door of British and European farming regulations in the article, the first time a member of the Royal Family has written for the magazine

Vegetables have disappeared from cultivation, due to a combination of excessively bureaucratic regulations and commercial pressures Prince Charles

The Prince has allowed BBC cameras to spend a year filming at his organic farm at Highgrove, Gloucestershire, for the BBC2 programme Natural World, to be shown on Sunday.

He says the countryside is being wrecked in the name of agricultural "progress".

He writes: "Our native breeds of farm animals are just as much a part of our cultural heritage as Sutton Hoo or Stonehenge.

"The threat to them is not, as in the past, that the last flock or herd is about to be sold, but the insidious pressure from ever-increasing European and national legislation which often has a disproportionate effect on rare breed keepers."

'Wealthy man's indulgence'

Charles describes his battle to protect ancient woodland, preserve native sheep, cattle and horses, from extinction and cultivate rarer vegetables on his Duchy Home Farm.

He writes: "Some people like to say that this is all part of a wealthy man's indulgence.

"They are entitled to their opinion. My aim is to make a long-term investment in what I hold to be genuine sustainability for the future."

The prince wrote that the disappearance of rarer vegetables and fruit had wiped out an important gene bank that should have been part of an "insurance policy" for our descendants.

Organic pessimism

He adds: "During the past 30 years, almost 2,000 traditional varieties of vegetables have disappeared from cultivation, due to a combination of excessively bureaucratic regulations and commercial pressures."

At Highgrove, he says, he is trying to restore and recreate what has been lost.

But Sean Rickard, former chief economist at the National Farmers' Union, writes in the same issue: "Organic is most certainly not going to be the way of the future.

"With a global population of nine billion in 2050, and with organic methods yielding about a half of conventional methods, we just don't have double the amount of land that would be required."

Natural World: Highgrove - a Prince's Legacy is on BBC Two at 1825 GMT on Sunday, 26 January.