Conservative connection in prison (5)
I believe the answer is:
clink
'prison' is the definition.
(I've seen this before)
'conservative connection' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'connection' becomes 'link' (link is a kind of connection**).
'c'+'link'='CLINK'
'in' is the link.
(Other definitions for clink that I've seen before include "Ringing sound - prison" , "Old London prison" , "Prison - knock glasses together" , "1 ac [COOLER]" , "Rattle of coins; prison (slang)" .)