キャスティングボート

noun

casting vote

The deciding vote cast by a presiding officer to break a tie. Used in formal meeting contexts.

• 議ぎ長ちょうがキャスティングボートを投とうじた。

  The chairperson cast the deciding vote.

noun

balance of power

Refers to a situation where a small group or party holds the deciding influence, especially in a hung parliament or coalition scenario. Often used in political commentary.