Sort of prisoner left us: may travel for safety abroad (9,6)
I believe the answer is:
political asylum
'travel for safety abroad' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'sort of prisoner left us' is the wordplay.
'sort of prisoner' becomes 'political'.
'left us' becomes 'asylum' (I can't explain this - if you can you should believe this answer much more).
'political'+'asylum'='POLITICAL ASYLUM'
'may' is the link.
Can you help me to learn more?
(Other definitions for political asylum that I've seen before include "refuge?" , "State protection" .)