Democracy by algorithm? Public attitudes towards AI in parliamentary decision-making in the UK and Japan

Abstract Parliaments are beginning to experiment with artificial intelligence (AI), but public acceptance remains uncertain. We examine attitudes to AI in two parliamentary democracies: the UK (n = 990) and Japan (n = 2117). We look at two key issues: AI helping Members of Parliament (MPs) make better decisions and AI or robots making decisions instead of MPs. Using original surveys, we test the roles of demographics, institutional trust, ideology, and attitudes toward AI. In both countries, respondents are broadly cautious: support is higher for AI that assists representatives than for delegating decisions, with especially strong resistance to delegation in the UK. Trust in government (and general social trust in Japan) increases acceptance; women and older respondents are more sceptical. In the UK, right-leaning respondents are more supportive, whereas ideology is weak or negative in Japan. Perceptions of AI dominate: seeing AI as beneficial and feeling able to use it raises support, while fear lowers it. We find that legitimacy for parliamentary AI hinges not only on safeguards but on alignment with expectations of representation and accountability.