enter the lists

To join an argument or competition. Now that you've entered the lists and decided to run for mayor, I hope you've prepared for the personal attacks that are likely to follow. Once my relatives start arguing, I usually leave the room rather than enter the lists.

Fig. to begin to take part in a contest or argument. He had decided not to stand for Parliament, but entered the lists at the last minute. The family disagreement had almost been resolved when the grandfather entered the lists.

Also, enter the fray. Engage in a fight or competition, as in He said he'd be willing to enter the lists well before the primaries, or Whenever people disagreed, she was eager to enter the fray. The first term uses the noun lists in the sense of "a barrier around the arena enclosing medieval jousting tournaments" and was being used figuratively by the late 1500s. The variant uses fray in the sense of "a noisy skirmish or battle," a usage from the late 1300s.

To engage in combat, rivalry, or competition. The term comes from medieval jousting tournaments, in which the list or lists was the barrier around the arena for such a contest. It was used figuratively already by Shakespeare (“Now is she in the very lists of love,” Venus and Adonis, 1592). In 1647 Nathaniel Bacon used the full expression, “The King, loth to enter the List with the Clergy about too many matters” (Historical Discourse of the Uniformity of the Government of England). The term is similar to the slightly newer eager for the fray or enter the fray, “fray” being a battle, skirmish, or other fight, usually of a noisy nature. The first originated as a direct quotation from Colley Cibber’s version of Shakespeare’s Richard III (5.3): “My soul’s in arms, and eager for the fray.” However, all these expressions appear to be dying out.