Weak politicians turning up in a sweat (4)
I believe the answer is:
stew
'sweat' is the definition.
(I know that sweat can be written as stew)
'weak politicians turning up' is the wordplay.
'weak' becomes 'w' (physics symbol as in W-boson).
'politicians turning' becomes 'ets' (I can't explain this - if you can you should give a lot more credence to this answer).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'w'+'ets'='wets'
'wets' back-to-front is 'STEW'.
'in a' acts as a link.
Can you help me to learn more?
(Other definitions for stew that I've seen before include "Fret" , "Dish of meat and vegetables cooked slowly in liquid" , "Cook - hash" , "Tight spot" , "Cook (in one's own juices?)" .)