Monarch seen with party worker (8)
I believe the answer is:
labourer
'worker' is the definition.
(labourer is a kind of worker)
'monarch seen with party' is the wordplay.
I cannot really see how this works, but
'monarch' could be 'er' (abbreviation for Elizabeth Regina, British Queen) and 'er' is located in the answer.
'party' could be 'labour' (Labour Party is an example) and 'labour' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for labourer that I've seen before include "Farmhand" , "Person who works with their hands" , "Unskilled worker" , "Hercules, perhaps?" , "He is said to be worthy of his hire" .)