Too many social workers, perhaps, holding policemen up (7)
I believe the answer is:
besides
'too' is the definition.
(I know that too can be written as besides)
'perhaps holding policemen up' is the wordplay.
'perhaps' becomes 'bees' (I can't justify this - if you can you should give a lot more credence to this answer).
'holding' indicates putting letters inside.
'policemen' becomes 'dis' (DI's, detective inspectors).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'dis' reversed gives 'sid'.
'bees' placed around 'sid' is 'BESIDES'.
'many social workers' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for besides that I've seen before include "Apart from" , "In addition, as well" , "to boot" , "Moreover" , "Anyway" .)