Confident about government's upswing (5)
I believe the answer is:
surge
'upswing' is the definition.
(I've seen this in another clue)
'confident about government's' is the wordplay.
'confident' becomes 'sure' (similar in meaning).
'about' is an insertion indicator.
'government' becomes 'g' (abbreviation for government).
'sure' placed around 'g' is 'SURGE'.
(Other definitions for surge that I've seen before include "Sudden rapid rise" , "Sudden upward movement" , "Sudden forward movement" , "Sudden large increase" , "Sudden increase, gush" .)