Move by government at last becoming economical (6)
I believe the answer is:
budget
'economical' is the definition.
(thesaurus)
'move by government at last' is the wordplay.
'move' becomes 'budge' (to budge is to move slightly).
'by' means one lot of letters go next to another.
'at last' says to take the final letters.
The last letter of 'government' is 't'.
'budge'+'t'='BUDGET'
'becoming' is the link.
(Other definitions for budget that I've seen before include "Plan financially" , "Financial estimate" , "Fiscal estimate" , "Limit of funds" , "Chancellor's plan" .)