Mock failing after Liberal leaves (9)
I believe the answer is:
imitation
'mock' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for imitation that I've seen before include "Simulated" , "created by the impressionist" , "produced by copyist?" , "Counterfeit" , "take-off" .)