Slight resistance restricts one working for solicitor (10)
I believe the answer is:
petitioner
'for solicitor' is the definition.
(I've seen this in another clue)
'slight resistance restricts one working' is the wordplay.
'slight' becomes 'petite' (I've seen this in another clue).
'resistance' becomes 'r' (electronics abbreviation).
'restricts' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'working' becomes 'on' (on can mean working or activated).
'petite'+'r'='petiter'
'i'+'on'='ion'
'petiter' enclosing 'ion' is 'PETITIONER'.
(Other definitions for petitioner that I've seen before include "One with a suit" , "One making appeal to authority" .)