party-line vote

A party-line vote in a deliberative assembly (such as a constituent assembly, parliament, or legislature) is a vote in which a substantial majority of members of a political party vote the same way (usually in opposition to the other political party(ies) whose members vote the opposite way). The term implies that the decision is irrelevant to the merits of the issue at hand or the political beliefs of individual members, but instead is dictated by party policy.