Tread on street with a politician (5)
I believe the answer is:
stamp
'tread' is the definition.
(thesaurus)
'street with a politician' is the wordplay.
'street' becomes 'st'.
'with' says to put letters next to each other.
'politician' becomes 'mp' (Member of Parliament).
'st'+'a'+'mp'='STAMP'
'on' is the link.
(Other definitions for stamp that I've seen before include "Impress (a pattern)" , "Impress with a mark" , "put one's foot down hard" , "Item for philatelist" , "Postal token" .)