Alicia Silverstone would "rather go naked than wear animals".

The 46-year-old actress - who went vegan in 1999 - has underlined her support for animals rights by posing naked in a new campaign for PETA, the world's largest animal rights organisation.

In the campaign video, Alicia explains: "I never, ever, get naked in TV, in film, nothin', never, nope - but I've done it for PETA because that's how much it matters to me."

The actress has also urged the public to seek out alternative materials to leather.

She said: "The amount of resources, water, food, oil for transport, the amount of energy that goes into making leather is extraordinary. It's just not sustainable. The Earth can't handle it."

Alicia has been speaking out about animals rights for years, and she's reiterated that she would never "wear animals" under any circumstances.

She said: "I'd rather go naked than wear animals."

Meanwhile, Alicia previously admitted that veganism has "revolutionised [her] world".

The actress also explained how she developed such a strong passion for animal rights campaign work.

The 'Clueless' star - who has published two cookbooks, 'The Kind Diet' and 'The Kind Mama' - shared: "I watched the documentary 'The Witness' and took a look at my dog Sampson and thought 'If I’m not willing to eat you, how can I continue to eat these other creatures that have the same desire to live, are just as funny, and have the same reaction to pain as my dogs?'

"I went vegan for the animals but the health transformation I experienced and continue to experience was extraordinary. This revolutionised my world at 21 and shaped my life and career tremendously."