The rabbits will be rampant next spring as Cadbury and Mars make the Caramel and Malteaster bunnies a more significant part of their Easter "novelty" chocolates fixture.

Cadbury is investing £1m in its Caramel Bunnies brand and in the new year will introduce the first bunnies shell egg packs (rsp: £9.99) comprising a 300g chocolate shell and five Caramel Bunnies.

"We're really focusing on Caramel bunnies," said Kate Knight, Cadbury brand manager for Easter. "It was the number one Easter novelty launch last year. Novelties are a growing part of the fixture."

Meanwhile, Mars is getting behind its £8.6m Malteaster Bunny line with a four-week TV campaign due to break in January as part of a £500k marketing spend for the brand.

"Easter is the season to be playful with innovation and the Malteaster Bunny benefits from being bang in line with the fun nature of the Malteser brand," said Mars Chocolate MD Fiona Dawson.

Other NPD includes limited-edition M&M's in "spring" or pastel colours and Mars is also adding the Rainforest Alliance-certified seal to the packaging of Galaxy large and luxury eggs for the first time.

Meanwhile, Cadbury is adding Spots v Stripes, Curly Wurly and Freddo eggs and it is also running a £5m ad push for Creme Egg called Goo Dares Wins.

Cadbury has also removed the plastic packaging from its medium and small eggs large eggs had plastic removed last year. Chocolates would be contained within the shells of medium and small eggs for the first time in more than a decade, said Knight.