backbench

剑桥词典

(the seats used by) members of the British Parliament who do not have official positions in the government or in an opposing political party
（英國議會的）普通議員蓆，後座議員蓆
The prime minister expects strong support from the Labour backbenches. 首相希望得到工黨後座議員的強有力支持。
a backbench revolt 後座議員的一次反抗
比較
front bench 返回 backbench