Vivienne Westwood wants people to ''buys less''.

The 78-year-old designer insists drastic action is needed to tackle climate change and thinks the most important thing consumers can do is ''reduce, reuse, recycle''.

She said: ''Something has got to happen this year, or else we're too late.

''It's not enough to just live the life you've got already. You've got to stick to the three Rs: reduce, reuse, recycle...

''You reduce the clothes you're buying, you buy quality not quantity, [and] make sure you want to keep on wearing it. Go to work in an evening dress if you want.''

Vivienne believes her work as both an activist and a designer have become entwined because ''each helps the other'' as looking ''great'' helps someone be taken more seriously.

Speaking in conversation with Naomi Campbell for British Vogue, she said: ''It's very, very important to look great if you want to make a point, because then people [take you seriously].''

Naomi credited a conversation she had with the designer when she was just 16 years old for igniting her interest in philanthropic endeavours.

Recalling the tea she and her friend Kate Moss had shared with Vivienne, she said: ''You sat us down and gave us a talking to about being conscious in the world.

''That had a big impact on me. It was around the time that I started working with Nelson Mandela in South Africa, so it was all new to me still. You know, they have these posh words for it now, like philanthropy. For me it was just like, you do it because you want to do it.''