fling (throw) down the gauntlet

Cultural

To issue a challenge: “The candidate flung down the gauntlet and challenged his opponent to a debate.” A gauntlet was a glove; the wearer would throw it to the ground to show that he was challenging an opponent to fight.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023