"We've felt a little bit tied up in bureaucracy. We're getting there but we've had to fight every inch of the way," said Ian Low, director of Hemcore, the biggest UK hemp company.

Industrial hemp was banned until 1993 even though it contains a mere 0.2 percent of THC, the main active ingredient of the narcotic.

Hemp growers still need a licence to farm it, and have had trouble separating public perception of it from the its narcotic relative.

"It's a real industry...and we don't want it hijacked by the marijuana brigade," said Low.

Producers argue that its environmental benefits and commercial opportunities could help wildlife and revitalise farming and, although its original uses in paper and cloth are now small-scale in Britain, new technologies could employ it in a whole range of applications.

HEMP FOR HORSES

Hemcore recently gained the prestigious Royal Warrant for its hemp horse-bedding after five years of supplying it to the queen's stables, but sees a potentially more important use in the car industry.

Industry figures show car makers used 10,000 tonnes of plant fibre - including hemp - in 2001. It acts as an insulator against sound and cold in door and roof panels.

Hemcore already supplies hemp to German car makers BMW and Mercedes, and estimates demand could be in the hundreds of the thousands of tonnes by the end of the decade.

"We could see it building up very rapidly over the next couple of years," Low said.

Government figures show 2,500 hectares were grown in Britain in 2001. This is still minute compared to the approximately two million hectares of wheat but Hemcore alone is planning to increase the area devoted to hemp by half this year.

Germany grows a similar area, while France grows more than twice as much, Low said.

Others in the industry say a hemp boom could benefit the rural economy and help it to climb out of the slump caused by the BSE and foot-and-mouth animal diseases.

"It could revitalise the farming economy," said Derek Bielby of the Yorkshire-based Hemp Union, which makes hemp clothing and products, and grows and processes its own crop.

PAPER AND CLOTH

Although it formed the paper for such famous documents as the Magna Carta, the first King James Bible and a draft of the U.S. constitution, the only hemp paper you're likely to notice now is - appropriately enough - large cigarette papers.

Its other traditional use was in cloth - hemp gave the fibre for the first U.S. flag as well as the British navy's sails and ropes - but despite a few fashionable users like Giorgio Armani, it is generally considered too rough a fabric.

But processors have branched out, and its construction uses extend beyond just keeping heat in and noise out of cars. The Suffolk Housing Council finished two houses made largely of hemp last year, and is monitoring how they perform.

Richard Scales, a partner at the architects' firm that designed the houses, said tests were proving positive.

"Preliminary results show that it's actually using less energy than traditional houses," he said.

Scales said the hemp/lime mix acts as bricks, insulation and water-proofing in one, and although it is still very much on the fringes of building practice, he expected it to become more mainstream.

Sarah Yearsley of Sussex-based hemp food firm MotherHemp said the seeds were another key element of the crop, as they contained all the essential fatty acids used by the body as building blocks for proteins.

GREEN GRASS

But growers and users of hemp point mainly to the crop's environmental credentials as its chief advantage.