Problem protecting councillor in disorderly crowd (5)
I believe the answer is:
scrum
'disorderly crowd' is the definition.
(I've seen this before)
'problem protecting councillor' is the wordplay.
'problem' becomes 'sum' (arithmetic problem).
'protecting' indicates putting letters inside.
'councillor' becomes 'cr' (I've seen this in other clues).
'sum' placed around 'cr' is 'SCRUM'.
'in' is the link.
(Other definitions for scrum that I've seen before include "A rugby play" , "Rugby-players crouch here" , "Rugby gathering?" , "A rugby formation or confused struggle" , "brawl" .)