English political party make speech that's highly detailed (9)
I believe the answer is:
elaborate
'highly detailed' is the definition.
(I've seen this before)
'english political party make speech' is the wordplay.
'english' becomes 'e' (abbreviation).
'political party' becomes 'lab' (abbreviation for Labour Party).
'make speech' becomes 'orate' (oratory is public speaking).
'e'+'lab'+'orate'='ELABORATE'
'that's' acts as a link.
(Other definitions for elaborate that I've seen before include "Complicated - complex" , "Expand (upon)" , "Polish" , "Ostentatious, possibly" , "Complicated - work out" .)