Holly Willoughby has admitted she has a ''hidden'' feisty side.

The 37-year-old television presenter has revealed that whilst she might appear happy on screen, she has a secret fiery side hidden beneath, which often comes out during her hosting duties on UK skating competition 'Dancing on Ice' when she thinks judge Jason Gardiner is being unfair to the celebrity skaters.

When asked if she has a feisty side, and who the last person to witness it was, Holly said: ''Yes, I think so! It's fairly hidden beneath, but when it needs to come out, it's definitely there. You probably see that side of me on a Sunday evening when Jason Gardiner is being harsh on one of our celebrity skaters. He gets a bit of my feisty side.''

But the blonde beauty doesn't have a name for her feisty alter-ego such as Beyoncé's Sasha Fierce, because she doesn't think she shows that side of herself often enough.

Asked if she has a name for herself when she's being feisty, Holly said: ''I would love to give it a name, but I don't think my feisty side is big enough to have its own name. I think there is a way of being feisty, without being angry or fierce - I like to think I'm a mix of feisty and charming!''

The 'This Morning' presenter made the comments as she helped to launch the new 'Because I Can' campaign for Diet Coke, for which she is an ambassador.

The campaign will see the brand encourage fans to live their life unapologetically, through trying the new flavours of the low calorie beverage, including Feisty Cherry and Exotic Mango.

Speaking about the rarely-seen sides of her personality, Holly said: ''I can definitely be feisty sometimes, so it has been fun to play with the cherry and mango themes. The new Diet Coke flavours offer an exciting twist on classic Diet Coke and a fresh alternative for fellow fans of the original.''

The new flavours of Diet Coke will be available in stores in March.