Pass time in parliament (4)
I believe the answer is:
diet
'parliament' is the definition.
(thesaurus)
'pass time' is the wordplay.
'pass' becomes 'die' (I've seen this before**).
'time' becomes 't'.
'die'+'t'='DIET'
'in' is the link.
(Other definitions for diet that I've seen before include "Restrict food-intake" , "Range of food eaten" , "go without sugar perhaps" , "Choice of food" , "Slimming regime" .)