Of a mind to support exit of a branch of government (12)
I believe the answer is:
departmental
'a branch of government' is the definition.
I can't judge whether this definition defines the answer.
'of a mind to support exit' is the wordplay.
'of a mind' becomes 'mental' (I can't justify this - if you can you should give a lot more credence to this answer).
'to support' means one lot of letters go next to another (in a down clue, some letters hold up others).
'exit' becomes 'depart' (I've seen this in another clue).
'mental' put after 'depart' is 'DEPARTMENTAL'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for departmental that I've seen before include "Relating to a division of a large organisation" , "Divided into sections" , "Organised in units" , "like some big stores?" , "Sort of store" .)