Wind up supporting British sausage (6)
I believe the answer is:
banger
'sausage' is the definition.
(banger is a kind of sausage)
'wind up supporting british' is the wordplay.
'wind up' becomes 'anger' (wind up can mean to annoy or anger).
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'anger' after 'b' is 'BANGER'.
(Other definitions for banger that I've seen before include "It might just drive" , "Old rattling car or slang sausage" , "set off on November 5" , "Explosive" , "Noisy old car or slang sausage" .)