I'm fairly politically switched on - I know what all these systems mean, for example - and the sudden appearance of supplementary vote still caught me out. (politics.stackexchange.com)
«21 Tory rebels object to supplementary vote for election of city mayors Main Philip and David Davies lambast the Government over its law and order policies» (conservativehome.blogs.com)
The London mayor is elected by supplementary vote, with each allowed to choose a first choice and a second choice. (totalpolitics.com)