Raisins are the key ingredient in the latest Toblerone variant, which marks the biggest investment in the brand for more than 10 years.

Manufacturer Kraft Foods is now trialling Toblerone Fruit and Nut before its launch later this summer.

The extension, which will feature purple and gold packaging, will be available in 400g and 100g bars in multiple retailers.

Only the smaller format will be available to the independent sector.

"Toblerone is one of the world's top selling chocolate brands, with the UK market accounting for nearly one third of total EU retail sales," said customer director Dave McNulty.

"It is important to revamp brands to excite customers and to attract a new market."

The fruit and nut variant combines the original Swiss milk chocolate, honey and almond nougat, with whole raisins. "We chose to launch a fruit and nut variant as there is a huge opportunity within the sector, which is worth £68m and growing," he said.