This chapter examines whether metropolitan voting behaviour in London and Rome has exhibited patterns of polarisation. It traces electoral outcomes across the 2000s, 2010s, and early 2020s to assess whether vote “metropolitanisation” intensified alongside the consolidation of the transnational cleavage. The analysis finds growing electoral heterogeneity and polarisation within metropolises, although there are no consistently linear trends. GAL parties thrive in central districts, while TAN parties gain traction in suburban and peripheral areas. Importantly, the surge of TAN and populist radical right parties coincides with their increasing “suburbanisation”. Although trends vary over time, the evidence shows that electoral polarisation within metropolitan areas has overall deepened, with the GAL–TAN axis producing more pronounced divides than those associated with traditional centre-left and centre-right competition.