The flower sprout - a cross between a Brussels sprout and kale - is tipped to go mainstream as more retailers get the chance to sell the veg.

At present, Marks & Spencer has the exclusive right to sell the flower sprout in the UK, but the exclusivity period expires in January.

The flower sprout is described as a superfood because of its high levels of vitamins C, E and B6. Tozer Seeds, the company that developed the vegetable, said sales had been good since it went on sale in M&S in 2010.

“Consumers like the appearance and flavour, and they find it easy to wash and prepare,” said Tozer Seeds UK sales director David Rogers.