pull the rug out from under

Idioms  

1. 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]

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Example Sentences

“I think that you need to center the needs of the people that you’re trying to help and ask, ‘Does it serve someone to pull the rug out from under them?’”

From Los Angeles Times

“These people did everything right — they applied through a lawful program, they were vetted. And to pull the rug out from under them in this way should be, I think, offensive to our own idea of what justice is in this country.”

From Los Angeles Times

Comprehending the way Martin set up Ned on the page to be the triumphant hero, only to pull the rug out from under his readers, is one matter.

From Salon

This masterful twist left everyone thinking Smithy had said yes… only to pull the rug out from under us.

From BBC

The Yankees, you could say, were threatening to pull the rug out from under the Orioles.

From Washington Post