Party for the scientists from old, old city (6)
I believe the answer is:
labour
'party' is the definition.
(I know that Labour is a type of labor party)
'scientists from old old city' is the wordplay.
'scientists' becomes 'lab' (I can't justify this - if you can you should believe this answer much more).
'from' says to put letters next to each other.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'old city' becomes 'ur' (ancient city state).
'lab'+'o'+'ur'='LABOUR'
'for the' is the link.
Can you help me to learn more?
(Other definitions for labour that I've seen before include "Left - work" , "unnecessarily elaborate" , "hands?" , "Productive work" , "End of term" .)