An opponent; a person who objects to or opposes a plan, idea, or policy.
新しい開発計画には地域の反対者が多く集まった。
Many local opponents gathered against the new development plan.
会議で彼は反対者として意見を述べたが、建設的な提案も出した。
He spoke as an opponent at the meeting, but also offered constructive suggestions.
政策の反対者と支持者の間で激しい議論が交わされた。
Intense debates took place between opponents and supporters of the policy.