The world's largest blackberry is set to go on sale, and no it's not everyone's favorite handheld PDA of choice, but rather, the actual soft fruit itself.

Marks and Spencer stores in the UK will sell 'king-sized' blackberries that are about 3-4cm long, and were first discovered in New Zealand. The British retailer predicts that shops nationwide will sell out of the oversized fruit.

Marks and Spencers have also sold king-sized strawberries, blueberries, and cherries in the past as well.

According to Ananova, Emmett Lunny, Marks and Spencer specialist, said: "It has a fantastic sweet taste - it just melts in your mouth."

"Demand for delicious and unusual fruit is huge as people want healthy food to snack on."

Blackberry sales doubled in the UK over the last year.