London Fashion Week 2009 has put ethical clothing at the top of the fashion agenda - and the boutique owners and designers of Portobello Road are leading the way.

The 25th annual celebration of frivolity and Britain's edgy style has this year been dominated by green, sustainable fashion as the estethica exhibition and show took centre stage with 37 designers showing compared to 13 last year.

Co-curated by Orsola de Castro (pictured), who has run From Somewhere in Portobello Road since 1997, with Filippo Ricci and The British Fashion Council, estethica opened the catwalk shows on Friday with an announcement by Lord Hunt of Defra about the new Sustainable Clothing Action Plan. It is the busiest and most buzzing section of the exhibition at the Natural History Museum that closes today.

Huge amounts go to waste in the 'pre-sumer' stage of manufacturing and many of the exhibitors use material snatched from factories and storage hangers like Christopher Raeburn's stylish macs and bomber jackets made from government surplus parachute material.

Others champion traditional and organic methods such as Eloise Grey , whose high-quality natural tweed coats and suits give a newly price-concious consumer a product that will last.

"It is the great revolution" said Orsola, who uses disabled and disadvantaged workers in a cooperative near Venice in Italy to make the knitwear and British tailors for the girly dresses sold in west London's hippest street. "You can eat organic broccoli until the cows come home and no one will know but if you wear an ethical label it makes a statement.

"We are changing the industry from within. Ethical fashion has been seen as rough around the edges with things like sack hemp but we are challenging those preconceptions."

It is not just designers who are changing the way clothes are made. An array of new fabrics and new ways of treating age-old materials is being developed in laboratories around the world, offering designers new options if they want to stay ethical. Peace Silk, used by designer Ivana Basilotta, is manufactured in a process where no silk worms are killed. Hemp can now be manipulated in ways that challenge the old hemp-sack look and man-made fabric Tencel - made from beech trees - is gaining popularity.

Outside of the exhibition designers clamour to join the green revolution. Bag makers rush to prove that their Acacia designs are made from sustainable wood and even the look of the jewellery and much of the clothing on offer this year is more earthy and natural despite the expected presence of gold trousers and lots of shoulder pads.

In the run-up to the shows worries about models' shrinking waistlines were this year replaced by fears that shrinking wallets could keep buyers away and many of the smaller, greener designers reported a lack of cash being flashed from potential stockists. The will and interest in ethical fashion is there, but the real money lags behind.

Orsola says buyers are being slow to realise the about-turn in consumer expectations and fears the recession could prove disastrous if buyers opt for the cheap mass-production of China and India to keep costs low.

Her store From Somewhere also stocks the classy Nina Dolcetti shoes made by fellow exhibitor Elisalex Grunfeld De Castro, 24, an 'upcycler' who uses offcuts, scrap and colour swatches to make her towering snakeskin heels and purple riding boots. She supports British artisans to sole and heel her collections and worries that British shoe-making is a 'dying art'.

She believes that past six months of economic turmoil has produced consumers who desire a 'less guilt-ridden' purchase and that the designers most able to ride out the recession will be the ones who listen to shoppers.

Young London designer Ada Zanditon , 26, is out to push eco-friendly clothes into the luxury market at her first showing at London Fashion Week. Her stunning gowns and jackets use a silk she had made by traditional weavers Vanners, another art at risk in the UK. But is is her organic cotton dress, hand dyed with berries in her kitchen sink and on sale for £2,500, that shows how high ideals can make high end fashion and bring in the buyers. "The luxury market influences the rest of the market, "she said. "You must make it a real trend among influential people who are not necessarily ethical."

Alex McIntosh, business development manager of the Ethical Fashion Forum, said the interest in ethical fashion has been higher than ever this year and points to the new MA in Fashion and the Environment at the London College of Fashion as the shape of things to come.

He said: "One reason for that is that if you have got a complete economic meltdown people start to reassess their values.

"Sustainable isn't just about organic cotton and fair trade, it's about reducing the amount you consume.

"This is about more than a trend, it's a complete change of ethos."