Criminal opportunity offered by Conservative? Not at first (9)
I believe the answer is:
accessory
'criminal' is the definition.
(accessory is a kind of criminal)
'opportunity offered by conservative? not at first' is the wordplay.
'opportunity' becomes 'access' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'offered by' says to put letters next to each other.
'conservative?' becomes 'tory' (Tory means a member of the Conservative Party).
'not at first' means to remove the first letter.
'tory' with its initial letter taken off is 'ory'.
'access'+'ory'='ACCESSORY'
Can you help me to learn more?
(Other definitions for accessory that I've seen before include "Confederate" , "One assisting a crime" , "Hat or handbag, say" , "Matching gloves, for example" , "Someone who helps another commit a crime" .)