Aldi has posted an open letter to Channel 4 following a Caterpillar Cake challenge on last night's (Nov 14) 'Party Week' episode of Great British Bake Off. The technical challenge saw the quarter finalists take on the task of making a caterpillar cake.

Chocolate caterpillar cakes have been a British staple for many when it comes to birthdays and other celebrations. Many retailers offer their own version, including Marks and Spencer's 'Colin Cake' and Aldi with its Cuthbert The Caterpillar.

In a tongue and cheek post aimed at the Channel 4 show, Aldi took to its Facebook page to share its response to the challenge. In an open letter, packed full of puns, Cuthbert’s 'legal team' made their feelings know.

"To Channel 4, we are intellectual caterpillar counsel to Aldi UK," the post begins with. "We write to you regarding Channel 4’s violation of Cuthbert’s rights. Aldi has always been a big fan of the Great British Bake Off, and we’ve long craved a Hollywood handshake... But tonight's episode really took the biscuit.

"A caterpillar cake? Do you think that has legs? As I’m sure you know, Aldi is a globally recognised leading retailer of caterpillar cakes and we believe this infringes upon our copyright."

It goes on to say: "At the moment this is just us putting out our feelers. We’re larvaes, not fighters. We don’t want a frosty relationship and we’re certainly not trying to sponge off you.

"However, Aldi is prepared to protect its caterpillar and pursue this matter to the fullest extent of the law. We certainly think a legal challenge would be a piece of... well, we think it would be easy.

"Therefore we demand that you cease and desist from all further use of, and agree to permanently refrain from, any unlawful reference to, or use of, Cuthbert, including, without limitation, use of the image unless the team crown Aldi Star Bakers for the rest of the series (whilst Paul is dressed as a caterpillar)."

It signs off with: "Hopefully this isn’t a case of us trying to have our cake and eat it, and we can avoid a Great British Face Off. Kind regards, Cuthbert’s legal team."

A spokesperson at Aldi has confirmed there is no current legal action against Channel 4. But they do say: "amateur bakers might want to consider buying a caterpillar cake before they attempt to make one at home."

Many Aldi fans found the letter hysterical, with the post gaining a whopping 29k likes and thousands of comments from amused Facebook users. Emma replied: "you most definitely have one of the best marketing teams about, very well played once again."

Jackie joked: "I love a food fight. Brilliant!!" Rachel said: "Brilliant! Whoever writes these needs an award!!!" Donna added: "This is hilarious. Thank you Aldi for giving me a laugh when I needed one." Clare declared: "Winner of the Internet today."

During Tuesday night's show, the bakers were asked to make a light sponge with a chocolate ganache, decorated with meringue features. Matty was awarded Star Baker, while Cristy was sent home. Next week's semi-final will see the remaining finalists take on three patisserie challenges.