Put one's foot down seeing expert cover Electra complex (10)
I believe the answer is:
accelerate
'put one's foot down' is the definition.
'expert cover electra complex' is the wordplay.
'expert' becomes 'ace' (ace is a kind of expert).
'cover' is an insertion indicator.
'complex' indicates an anagram.
'electra' is an anagram of 'celerat'.
'ace' enclosing 'celerat' is 'ACCELERATE'.
'seeing' acts as a link.
(Other definitions for accelerate that I've seen before include "Go faster" , "snowball" , "Increase speed" , "Quicken" , "Crank up" .)