Fighting former PM naked (3)
I believe the answer is:
row
'fighting' is the definition.
'former pm naked' is the wordplay.
'former pm' becomes 'brown' (Gordon Brown, British Prime Minister 2007-2010).
'naked' means to look at the middle letters.
The centre of 'brown' is 'ROW'.
(Other definitions for row that I've seen before include "Informal quarrel or a straight line" , "File" , "'Quarrel, dust-up (3)'" , "Paddle" , "Propel boat by manual means" .)