Desert people in a struggle for survival (3,4)
I believe the answer is:
rat race
'struggle for survival' is the definition.
'rat race' can be an answer for 'struggle' (I have seen 'Daily struggle ' mean 'rat race' so perhaps 'struggle' could also mean 'rat race'). I am not sure about the 'for survival' bit.
'desert people' is the wordplay.
'desert' becomes 'rat' (abandon treacherously).
'people' becomes 'race' (people can mean a national group or race).
'rat'+'race'='RAT-RACE'
'in a' acts as a link.
Can you help me to learn more?
(Other definitions for rat race that I've seen before include "The struggle for success" , "keen contest" , "struggle for position" , "Fiercely competitive working life" , "Daily struggle to get on" .)