pull the plug prevent something from happening or continuing; put a stop to something. informal
☞ This phrase alludes to an older type of lavatory flush which operated by the pulling out of a plug to empty the contents of the pan into the soil pipe.
2013Alf Grumble Pulling the plug on funding for the Healthy Eating Healthy Action programmes and allowing the junk food industry free rein over our young kiwis is … creating a sad legacy of increasing diabetes and chronic diseases.