Economy shift by Tory leader (6)
I believe the answer is:
budget
'economy' is the definition.
(I've seen this before)
'shift by tory leader' is the wordplay.
'shift' becomes 'budge' ('budge' can be a synonym of 'shift').
'by' means one lot of letters go next to another.
'tory leader' becomes 't' (I've seen this in other clues).
'budge'+'t'='BUDGET'
(Other definitions for budget that I've seen before include "Plan of spending" , "Money allocated for a purpose" , "Financial estimate" , "Funding plan" , "Financial plan - inexpensive" .)