shoot (one's) fox

To undermine or thwart someone's plans, efforts, or ambitions by taking action that pre-empts them or makes them redundant. Primarily heard in UK. Congress may have shot the president's fox, though, with a bill that he cannot politically afford to veto, but which leaves him with no opportunity to pass his signature healthcare plan.

shoot someone's fox

thwart someone's plans or ambitions by pre-empting them.

The expression comes from the world of fox-hunting, where shooting a fox, which robs the hunters of their sport, is viewed with great displeasure.

2004 Scotland on Sunday The Democrats had planned to make unemployment a key issue in their campaign: Dubya, with his tax cuts, has shot their fox.