cut the ground from under somebody/somebody's feet

cut the ground from under(neath) (one's) feet

To suddenly cause problems for one. I plan to cut the ground from underneath the prosecutor's feet with this line of questioning.
See also: cut, feet, ground
Farlex Dictionary of Idioms.

cut the ground from under

Unexpectedly withdraw support or destroy one's foundation, trip someone up. For example, Overriding his veto, Congress cut the ground from under the President. This metaphoric phrase alludes to removing the solid earth from under someone. [Mid-1800s]
See also: cut, ground
The American Heritage® Dictionary of Idioms by Christine Ammer.

cut the ground from under somebody/somebody’s ˈfeet

suddenly spoil somebody’s idea or plan by doing something to stop them from continuing with it: When he announced that all my figures were out of date, he really cut the ground from under my feet.
See also: cut, feet, ground, somebody
Farlex Partner Idioms Dictionary
See also:
  • cut the ground from under someone's feet
  • cut the ground from under(neath) (one's) feet
  • underneath
  • cut the ground out from under
  • cut the ground out from under (one)
  • cut the ground from under
  • cut the ground from under (someone)
  • cut the ground from under someone
  • cut a fat hog
  • cut eyes at