have the whip hand

have the whip hand

To have the most power or influence in a particular situation or setting. As the editor in chief, I have the whip hand and give final approval for the layout of every issue—remember that.
See also: hand, have, whip
Farlex Dictionary of Idioms.

have the whip hand

or

hold the whip hand

If you have the whip hand or hold the whip hand in a situation, you have more power than the other people involved, and so you have an advantage or control over them. Consumers will be in the unusual position of having the whip hand over the agents. As the Democrats have majorities in both Houses and therefore control the relevant committees, they now seem to hold the whip hand.
See also: hand, have, whip
Collins COBUILD Idioms Dictionary, 3rd ed.

get, have, hold, etc. the ˈwhip hand (over somebody)

have power or control (over somebody): The government knows that the army have the whip hand. Our opponents had the whip hand over us right from the beginning.
See also: hand, whip
Farlex Partner Idioms Dictionary
See also:
  • hold the whip hand
  • get the whip hand
  • get, have, hold, etc. the whip hand
  • whipping
  • under the influence
  • whip (someone or something) on
  • whip on
  • backstairs influence
  • the whip hand
  • under the influence of alcohol