Cara Delevingne and Kate Moss are undoubtedly Britain's biggest supermodels and it's only fitting that the duo should have a pose off in a sexy selfie swap which has taken Instagram by storm.

The 23-year-old totally turned up the heat with a provocative photo that she posted on September 23. The former model posed topless while using her hands to draw attention to her superhero undies for what appeared to be an impromptu photoshoot with the 41-year-old supermodel.

“SUPER WOMEN photo taken by Miss Moss #KateMoss #selfieswap @mertalas,” Cara captioned the photo. The former model posed topless on a messy bed wearing nothing but a pair of undies, a white coat, and an array of rings and bracelets on her hand.

The second image sees veteran model Kate shoot the camera a sultry look as she writhes around on an unmade bed in black underwear and opaque tights.

"SUPER KATE! Photo take by myself #KateMoss @mertalas #selfieswap," Cara wrote alongside the snap, which garnered almost as many likes.

Kate and Cara have become firm friends and have numerous joint campaigns under their belt, including luxury British brand Burberry and high street store Mango.

They are currently in Milan together, where they attended a Mango photocall arm-in-arm after also appearing together on the front row at London Fashion Week's Burberry presentation on Monday.

Cara previously referred to Kate as her idol and 'partner in crime', saying of their new Mango collaboration: "We are a lethal combination."

"I admire her personally and professionally, she represents a true fashion icon. It is a privilege to learn and to share this experience with her."

While Cara announced that she will no longer strut down the catwalk for big fashion designers, it looks like she still has a few modeling campaigns up her sleeve.

Yves Saint Laurent Beauty revealed a sexy make-up ad starring Cara at the end of August 2015. The British actress posed in literally nothing but bright red lipstick and a fitted black Saint Laurent jacket.