Upset your apple cart - Idioms by The Free Dictionary
upset (one's) applecart (redirected from upset your apple cart)
upset (one's) applecart
To ruin or interfere with one's plans or goals. Look, he's not trying to upset your applecart or anything—he just needs to meet later in the day now, that's all. I had some ideas on how they could improve things, but I didn't want to upset their applecart this late in development.
upset the/somebody’s ˈapple cart (informal) do something that spoils a plan or stops the progress of something: Another, much cheaper hairdresser has opened next door, which has upset the apple cart.
References in periodicals archive
After you've talked to an individual senator and gained his or her support, you can walk away in the sure and certain knowledge that no interfering political boss will later upset your apple cart
. The merits of your case will not be undermined by irrelevant factors.