Alexa Chung speechless as Portrait Artist of The Year contestant urges her to sit with her legs open in dress

ALEXA Chung received quite the cheeky instruction as she posed to be painted on Portrait Artist of the Year.

The Sky Arts show is normally as chilled as Bob Ross and his happy little trees, seeing both pro and amateur artists render famous people in paint, but took quite the turn after the 37 year old was urged to uncross her legs in a minidress.

In a clip from tonight’s episode, the Next in Fashion stunner is one of three celebs invited along to The Grand Hall of Battersea Arts Centre.

The brunette beauty explains that, although she’s no stranger to the camera, which she feels is “collaborative”, she’s not used to giving away control like you have to as a painter’s subject.   

The artists get just four hours to complete their portraits, and they always kick off with a brief chat with the celebs about how they should position themselves. 

Alexa makes it clear that she feels most comfy cross-legged, but one of the painters swiftly warns her this is a bad idea. 

“So they say, ‘don’t cross your legs’”, she explains as Alexa’s jaw hit the floor. 

“Don’t cross my legs?!” the model and designer asks in response, before insisting it would be a challenge to sit any other way. 

The contestant went on to inform Alexa her legs could go dead if she sits like that for four hours. 

“Ok. God, it’s so my instinct to cross them,” Alexa replies, struggling to find the right position. 

The TV presenter gets there eventually, and after relaxing and finding her stride is the picture of glam.

The only problem was the outfit matched the chair, meaning the artist may find it hard to distinguish subject and seat...

Viewers can find out how the contestant tackled the tricky issue in tonight’s episode of Portrait Artist of the Year, where comedian Nish Kumar and actor Philip Glenister also appear as sitters.

Presented by Stephen Mangan and Joan Bakewell, the therapeutic programme has attracted big names including actress Kelly Macdonald and Autumnwatch co-host Chris Packham. 

Replacing swords with brushes, the contestants battle it out to win a whopping £10,000 at the end of the series.