drive a coach and horses through
drive a coach and horses through (something)
To expose the flaws in something, such as a statement, argument, or belief. Primarily heard in UK. The suspect had said he wasn't there that night but then drove a coach and horses through that idea with today's contradictory statement.
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 throughmake something entirely useless or ineffective. British
An early example of this idiom is found in this statement by the Irish lawyer Stephen Rice ( 1637–1715 ): ‘I will drive a coach and six horses through the Act of Settlement’. Early versions of the phrase also refer to a space big enough to turn a coach and six (or four ) (i.e. horses) in, but the context, following Rice's declaration, is very often that of rendering a law or regulation ineffective.
1997 Spectator A coach and horses was driven through one of the guiding principles of American statecraft.