Range Rovers will be the basis of what is claimed will be the “most luxurious and exclusive off-roader ever”.

Only 100 of the cars, designed and manufactured in conjunction with upmarket sporting gun manufacturer Holland & Holland and based on either the the 2010 model year 503 bhp supercharged or TDV8 Range Rover Autobiography, will be made.

Interior and exterior enhancements designed and manufactured in conjunction with Holland & Holland will be carried out by Overfinch, a Surrey-based engineering company that has been involved in producing exclusive Range Rovers in 1975.

The new car is being kept under wraps until it is launched at the Holland & Holland Shooting Grounds on September 23. The aim, according to Holland & Holland, is to create “an all-purpose all-season luxury supercar for the discerning few. The result is a quintessentially English take on luxury.”

Holland & Holland managing director Daryl Greatrex said: “It’s ten years since we had a Holland & Holland Range Rover and we decided that working with Overfinch was the only way to do it this time. Over the years it has become clear that what AMG is to Mercedes and Alpina is to BMW, so Overfinch is to Range Rover.”

Neil Underwood, chief operating officer of Overfinch, added: “There has always been a great deal of speculation that Range Rovers could approach Bentley levels of luxury – for 100 fortunate customers, that will now become a reality.

“We have worked closely with designers, engineers and the craftsmen of Holland & Holland, who have helped us create the most exclusive, most luxurious off-roader ever built.”