with one voice
Unanimously; in total agreement. Yes, the entire committee made that decision with one voice. The only way we'll convince our senators to change the laws is if we all stand together and speak with one voice.
with one voice
Unanimously, in complete agreement, as in The board rejected the proposal with one voice. [Late 1300s] For synonyms, see as one; to a man.
with ˌone ˈvoice
(of a group of people) in complete agreement: It’s very rare to find the unions and management speaking with one voice, but on the question of safety at work there is total agreement. with one voice
In complete agreement; unanimously.