Design colleges have a key role to play if ethically-produced products are to make the move from fringe to mainstream - even though educators themselves admit they face an uphill struggle in changing the mindset of the next generation of designers.

Postgraduate students are frequently not aware of environmental and sustainability issues, "and they're frequently not interested," laments Professor Clare Johnston, head of the textile program at the Royal College of Art.

"Students are too caught up in their own trajectory and their own future as a designer," agrees Professor Sass Brown from the Fashion Institute of Technology in New York.

It's "difficult for students to get a real understanding [of ethical issues] because it's not necessarily part of their experience at that time," adds Jane Rapley OBE, head of Central Saint Martins College of Art and Design.

She also points out that ethical issues cover "a huge territory", and that it's often easier for students to address ecological aspects of design "because it's about physical things and materials that they are dealing with as they hone their skills".

Delegates at this week's first annual Sri Lanka Design Festival in Colombo were, however, unanimous that design is one of the key drivers in the future uptake of sustainable fashion.

"Because the popularity of ethical products is all about the products themselves, they need to be design-led," notes Neil Chadwick, founder of the Seasalt ethical clothing brand.

"It needs to be interesting design, because at the end of the day consumers are going to buy what they consider to be good value," he explains.

That said, ensuring colleges are producing design students who understand the importance of ethically-produced products is likely to take a multi-pronged approach that takes in both education and society at large.

"I think the solution is to start really early on right back at school level, and introduce it right through the curriculum," explains Professor Johnston.

And Bruce Montgomery, professor of design craftsmanship at Northumbria University agrees that one of the ways of ensuring the ethical/sustainable message is reflected in the curriculum for fashion education "is to start to slowly introduce it into part of the modules within courses."

"I think our part in this as educators is to give students the knowledge and understanding of what the ramifications of their choices are, so they're not merely aesthetic but are ethical as well," points out Professor Brown.

She believes designers should be taught to understand the ramifications of every choice they make in the design process, from the sourcing of fabrics, to the chemicals used, and how garments are recycled.

But Jane Rapley believes students will only become engaged in the issue when it becomes part of the bigger context in which they're working.

"Education can't do it on it's own, it has to be part of the zeitgeist of what's around," she says.

"Once it becomes a much more debated question within our own societies, politics, and economics, can designers begin to understand it and address it...it has to be part of the bigger context."