Role played by youth leader in faction (5)
I believe the answer is:
party
'faction' is the definition.
(I've seen this in another clue)
'role played by youth leader' is the wordplay.
I cannot really see how this works, but
'role' could be 'part' (eg a part or role in a film) and 'part' is found within the answer.
'youth' could be 'y' and 'y' is present in the answer.
No letters remain.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for party that I've seen before include "Political organisation" , "eg Labour, Conservative" , "Festivity" , "Social occasion - political group" , "Celebratory social gathering" .)