pull the rug out from under

To suddenly or unexpectedly remove or rescind support, help, or assistance from someone; to abruptly leave someone in a problematic or difficult situation. I felt like someone had pulled the rug out from under me when my health insurance said it was going to stop paying for my medical bills. I'd love to quit my job, but I just can't pull the rug from under my team like that.

To suddenly or unexpectedly remove or rescind support, help, or assistance that one depended on; to abruptly leave one in a problematic or difficult situation. I felt like someone had pulled the rug out from under me when my health insurance said it was going to stop paying for my medical bills. I'd love to quit my job, but I just can't pull the rug out from my team like that. You really pulled the rug out when you said you were going to stop helping me pay my bills.

Remove all support and assistance from, usually suddenly. For example, Stopping his allowance pulled the rug out from under him, forcing him to look for a job . This metaphoric term alludes to pulling on a rug a person is standing on so that he or she falls. [Mid-1900s]

To upset someone’s plans or activities; to remove someone’s supports. The image is undeniably clear, but a more common practice, it would seem, would be the schoolboy trick of pulling a chair away from someone who is about to sit down. It is rug, however, that became part of a common turn of phrase, originating in the mid-twentieth century. Time used it in an article about labor and the economy in 1946: “Strikes, for instance, would pull the rug out from under the best of prospects.”