Striking claim by a working model (8)
I believe the answer is:
'striking' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for imposing that I've seen before include "Taking liberties" , "Dictating; impressive" , "Grand, impressive" , "Impressive in appearance" , "Impressive - or putting tax on" .)