With this year widely touted as the time 'eco-chic' finally takes off, the fashion for environmentally-responsible clothes has been boosted by celebrity endorsements by the likes of actress Sienna Miller.

A world away from the catwalks of Paris, London and Milan, companies in rural Wales are in the vanguard of the new movement.

Cardigan company Howies and Garthenor Organic Pure Wool of Tregaron can already boast fans as diverse as Prince Charles and Coldplay lead singer Chris Martin.

Sally King, who runs Garthenor with her husband Chris, said, 'Eco-fashion is the thing now. For a while people have been concerned about what they are eating, now they are becoming concerned about what they are wearing.'

Last year organic food sales in the UK were worth an estimated £1.2bn, double their value in 2000, and that trend now looks set to be mirrored in the ethical clothing market.

According to the Co-operative Bank's annual Ethical Consumption Report 2005, published last month, the UK market for ethical clothes has grown to £43m annually - a rise of 30% since 2003.

The movement has grown out of an increased awareness that producing textiles is among the world's 10 most polluting industries.

According to the Soil Association, cotton crops are sprayed with a quarter of the world's insecticides, many of which are highly toxic to humans and wildlife.

For Howies, this has led to a range of cool, skater-style sportswear inspired by a 'desire to make people think about the world we live in'.

The company, which sells its T-shirts in Japan in a collaboration with Paul Smith, introduced organic cotton jeans and is developing surfer shorts that change colour in polluted water.

In addition, it gives 1% of its turnover to environmental and social causes.

Garthenor Organic Pure Wool, meanwhile, produces garments using wool from its flock of 70 organic sheep.

All its products are in natural colours, undyed and unbleached, and Prince Charles, well-known for his green credentials, owns a jumper made by the Kings.

Mrs King added, 'It started by chance. I made some clothes for relatives and friends and they loved it, so we started mailing them out and now, thanks to the internet, we ship items out to the US and other countries.'

Mr King, a former BBC sound recordist who sits on the Soil Association's organic textiles standards committee, said, 'In order to be certified organic, our sheep and the farmland they graze, plus the subsequent processing of the fleece, all have to conform to Soil Association standards.

'They have to avoid the risk of contamination from any noxious chemicals and have regard for any effluent that could be produced.'

The company only uses the natural wool colours of its Shetland and Ryeland sheep, ranging from white and fawn through to brown and black.

'People are looking for ways of reducing or eliminating the 'poisoning' of the environment,' added Mr King.

'A lot of chemicals are used in farming and fabric processing, so it's good when people know that the fabrics they are wearing close to their skin are not contaminated.'

Wales' global green credentials will be further boosted by the Millennium Stadium's massive One Earth Concert to promote environmental awareness at the end of this month, featuring The Strokes and Super Furry Animals.

All in all, 2006 could well be the year when the words 'How Green was my Valley' take on a whole new meaning.