ON the banks of the River Severn the Cullimore family are serving up one of the rarest and most delicious of delicacies.

The tidal flow of the Severn estuary and the prime grazing lands that overlap it, provide the unique rich grasslands perfect for producing salt marsh lamb.

Such is the clamour for their product that the Cullimore family reported a 20% increase in the sales of their lamb in 2009, with sales of the current vintage about to start.

"Salt marsh lamb has a different flavour to regularly reared lamb," said John Cullimore, the fifth generation of the same family to farm the marshes close to the Wildfowl and Wetlands Trust at Slimbridge.

"It's difficult to explain how it differs, but when the customers try it they want more of it."

The Cullimore's farm was one of the first in Gloucestershire to go fully organic, doing so as long as 20 years ago.

The fact that the family farm organically means that their unique product is only on sale for part of the year. The current vintage will go on sale in mid-June and remain on sale until March 2010 or when it has all sold.

Because the family's insistence on a natural breeding cycle for their livestock it cannot be sold all-year round.

"We don't use any growth hormones or genetically modified agents when rearing our animals, they are allowed to grow naturally at their own pace," said John.

"It does mean that the product costs more to produce but it means that it is of the highest quality."

The Cullimore's sell their lamb at their small on-site farm shop, via their newly created website and at regular stalls at Farm Market's across the county.

"Until a year ago about a third of our meat was going to supermarkets, but that is no longer the case," said John. "Instead it's all sold directly to the public and when times are hard people like to support local businesses and their local community rather than the supermarkets."

"Everything we sell is produced here on the farm and the meat is all processed and packed within a distance of 10 miles.

"Our customers like the fact that they are buying a good local product."