The map illustrates how well proportional representation using the Single Transferable Vote (STV) could work for the UK Parliament.
Constituencies are based entirely on local authority areas, mostly electing 4 or 5 MPs; this gives a high level of proportionality, while maintaining a strong local connection. In England and Wales it is based as far as possible on traditional (``ceremonial'') counties.
Map of proposed constituencies (pdf)
Schedule of proposed constituencies (pdf)
Paper to appear in the Royal Statistical Society's journal, Significance (pdf)