Had visions of G-man arresting worker in present state (10)
I believe the answer is:
fantasised
'had visions of' is the definition.
(fantasise can mean to dream or have visions about)
'g-man arresting worker in present state' is the wordplay.
'g-man' becomes 'fed' (I've seen this in another clue).
'arresting' is an insertion indicator.
'worker' becomes 'ant' (worker is a type of ant).
'in present state' becomes 'as is' (as things currently are).
'ant'+'asis'='antasis'
'fed' enclosing 'antasis' is 'FANTASISED'.
(Another definition for fantasised that I've seen is " imagined better circumstances".)