pull the rug from under

pull the rug (out) from under (someone)

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.
See also: pull, rug
Farlex Dictionary of Idioms.

pull the rug (out) from under

Informal
To remove all support and assistance from, usually suddenly.
See also: pull, rug
American Heritage® Dictionary of the English Language, Fifth Edition.
See also:
  • brief (someone) about (someone or something)
  • brief about
  • accompany (one) on a/(one's) journey
  • accompany on a journey
  • a stranger to (someone or something)
  • be out of (one's) league
  • be out of somebody's league
  • be in bad with (someone)
  • (one's) heart goes out to (someone)
  • (one) puts (one's) pants on one leg at a time
References in periodicals archive
FLYING CARPET (3.05) can pull the rug from under the feet of some highly regarded rivals at Newmarket today.
Racing: FLYING CARPET TO FLOOR HER RIVALS
Trying its hardest to pull the rug from under Hitachi Data Systems Ltd, IBM Corp is offering Hitachi's 140 European bi-polar Skyline customers maintenance contracts, with the aim of converting them to IBM 9121 G5 CMOS processors.
IBM Aims to Convert Skylines to CMOS
President Clinton--who will, in due course, pull the rug from under Mr.
Who Needs NATO?
Blair still hopes Clinton will survive, and will not do anything to pull the rug from under him.
BLAIR HOPES PAL WILL SURVIVE
He said: "I wanted to pull the rug from under people.
Hot news, Derek's back
IT'S typical of Everton to build up your hopes one week, only to then pull the rug from under you the next.
The JURY: Alan Stubbs' experience may be more valuable than Yobo's pace in the derby - Spowart
but the leaders will be out to pull the rug from under the Clyde manager's feet today.
LIVINGSTON v CLYDE
Finally, after half a century out of the top flight, they find a manager who leads them back to the promised land - and then they pull the rug from under his feet.
Why's Mack been knifed?