Admission from a Conservative about English ship (6)
I believe the answer is:
access
'admission' is the definition.
(I've seen this in another clue)
'a conservative about english ship' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'about' becomes 'c' (abbreviation for circa).
'english' becomes 'E' (abbreviation).
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'a'+'c'+'c'+'e'+'ss'='ACCESS'
'from' acts as a link.
(Other definitions for access that I've seen before include "OK to go in" , "Doorway" , "Right or way to enter" , "Entry (code)" , "A way of approaching" .)