Not a Diva.
Let me provide you with a clue as this is I believe a hard one.
As far as I can ascertain, this is a one-off prototype by a known design company - perhaps for an established UK manufacturer. The car carries the name of the design company.
It has an Imp engine (modified by Manley) and is fitted with all-alloy bodywork.
The photo was cropped from a dealer' s listing when the car was for sale in the late 1970s/early 1980s.