Jack - it's the Chichester-Miles 'Leopard', a four-seat business jet. The one shown is the second of three protoypes built, and completed 84 test flights in 1997, powered by two of the specially designed jet engines, one of which is shown in the display case alongside the aircraft. Although it flew well, with good handling and performance, the project was eventually shelved, I think from lack of further funding, but not sure on that without checking with the museum.
It's a beaut of an aircraft, with an interior like a four seat sports car, and is less than one and a half metres in height, standing on it's landing gear.