Urge Independent politician to oppress the Spanish (5)
I believe the answer is:
impel
'urge' is the definition.
(impel can mean to urge or demand)
'independent politician to oppress the spanish' is the wordplay.
'independent' becomes 'i'.
'politician' becomes 'mp' (Member of Parliament).
'to oppress' is a charade indicator (letters next to each other) (in a down clue, oppress can mean goes on top of).
'the spanish' becomes 'el' ('the' in Spanish).
'i'+'mp'+'el'='IMPEL'
(Other definitions for impel that I've seen before include "Motivate" , "Egg" , "Urge or propel" , "Cause to move forward" , "Send or drive forward" .)