drive a coach and horses through
drive a coach and horses through something
Fig. to expose weak points or "holes" in an argument, alibi, or criminal case by [figuratively] driving a horse and carriage through them. (Formal. Emphasizes the large size of the holes or gaps in the argument.) The barrister drove a horse and carnage through the witness's testimony. The opposition will drive a coach and horses through the wording of that government bill.
drive a coach and horses through something(British)
if someone drives a coach and horses through a rule, an opinion, a plan, or a tradition, they destroy it by doing something against it which it is too weak to prevent His company drove a coach and horses through employment legislation. She produced statistics which drove a coach and horses through the chairman's argument.