Opinion polls as a linkage mechanism between the public and politics have rarely been examined in a parliamentary context. In our comparative study (Germany, New Zealand, Switzerland and the United Kingdom) we analyse if and how polls are invoked by MPs with different roles in parliamentary debates. Focusing on three theoretical aspects (responsiveness, populism and deliberation), we find that polls are indeed invoked to bring the views of the public into parliamentary debate to some degree, but they are also often used merely to support policies already developed in the political realm. Fears of the populist effect of polls are exaggerated; polls, in fact, have a positive influence on the discursive quality of parliament. Looking at parliamentary roles, we find very different patterns of poll use: while MPs oriented towards their constituencies use polls in the most direct and participatory vein, others mediate public opinion as displayed by polls through different institutions (the party, the parliament) or through expertise.