What one eats in parliament (4)
I believe the answer is:
diet
I believe this clue is a double definition.
'what one eats' is the first definition.
(I've seen this before)
'parliament' is the second definition.
(thesaurus)
'in' is the link.
(Other definitions for diet that I've seen before include "food one eats on a regular basis" , "Prescribed food - council" , "Food and drink regularly consumed" , "cut down" , "Fast - food - convention" .)