She's spent her career preaching about the evils of animal cruelty in the fashion industry.

But Stella McCartney has landed in hot water after a marketing campaign featuring a horse was branded 'exploitative'.

Photographs taken for the fashion designer - who refuses to use any animal products in her clothing lines - show model Kendall Jenner lying naked on the back of a white pony.

The reality star-turned-model, 27, who has been criticised in the past for wearing clothes made of fur and leather, wears just a pair of Ms McCartney's boots and holds a handbag in the shot.

Ms McCartney, 51, dubbed the campaign 'Horse Power' and said that her new 'Stella girl' was a 'next-gen horse lover and equestrian.'

Ms McCartney, 51, dubbed the campaign 'Horse Power' and said that her new 'Stella girl' was a 'next-gen horse lover and equestrian.'

Reality star-turned-model Kendall Jenner, 27, who has been criticised in the past for wearing clothes made of fur and leather, wears just a pair of Ms McCartney's boots and holds a handbag in the shot

She wrote on Instagram: 'A celebration of the timeless healing relationships between humans and horses. It is a collection of what Stella loves, crafted from 92 per cent responsible materials.

'The campaign is shot by Harley Weir at the Camargue Salt Flats in the south of France, among white ponies native to region - raised freely by horse whisperer Jean Francois Pignon.'

But many of Ms McCartney's social media followers were quick to criticise her for using an animal in an advertising campaign.

'Whether a horse is large or not, using them for profit disregards their flight instincts, making them uncomfortable around lights, cameras, and noises. Horses don't receive payment or have a choice in working,' one person wrote in the comments section.

Kendall Jenner posing with white horses. Ms McCartney wrote on Instagram: 'A celebration of the timeless healing relationships between humans and horses. It is a collection of what Stella loves, crafted from 92 per cent responsible materials'

Another follower wrote: 'I love this brand, its mission and vision, I don't find this photo campaign appropriate, especially if we have to protect animals and nature, this is a celebration of vulgarity and nudity.'

One posted: 'This is not a good campaign Stella McCartney, this is supporting exploitation of horses. You are promoting something that many of your patrons feel is cruelty to animals.'

'Horses have a strength that is almost hard for humans to understand, and even though I can't communicate with them directly, I feel that the ones I've cared for have always lent that strength to me,' said the model.

Ms McCartney, whose father is former Beatle Sir Paul McCartney and mother is the late animal rights activist Linda, received a CBE last year for her services to fashion and sustainability.

Ms McCartney says on her website that she has 'never used leather, feathers, fur or skin since day one' and uses 'innovative animal and cruelty-free alternatives.'

Ms McCartney was approached for comment.