Call for missile to tip unfavourable balance (5,3)
I believe the answer is:
trade gap
'unfavourable balance' is the definition.
'trade gap' can be an answer for 'balance' (I have seen 'negative balance' mean 'trade gap' so perhaps 'balance' could also mean 'trade gap'). I am not certain of the 'unfavourable' bit.
'call for missile to tip' is the wordplay.
'call for' becomes 'page' (to page is to call with a pager).
'missile' becomes 'dart' (dart is a kind of missile).
'to tip' says the letters should be written backwards (I've seen 'tipped' mean this).
'page'+'dart'='pagedart'
'pagedart' back-to-front is 'TRADE GAP'.
Can you help me to learn more?
(Other definitions for trade gap that I've seen before include "Excess of imports over exports" , "Import-export concern" , "'The difference between exports and imports (5,3)'" , "Economic deficit" , "negative balance" .)