First performance involving prime minister, European (8)
I believe the answer is:
premiere
'first performance' is the definition.
(I've seen this in another clue)
'prime minister european' is the wordplay.
'prime minister' becomes 'premier' (synonyms).
'european' becomes 'E' (abbreviation e.g. EU).
'premier'+'e'='PREMIERE'
'involving' is the link.
(Other definitions for premiere that I've seen before include "significant performance" , "Opening performance" , "First screening" , "Opening night" , "Mere pier (anag.)" .)