Unless an agreement is reached soon, the election will have to be conducted under the present single-vote system.

ECONOMIST: South Korea

Northern Ireland will elect three members under a separate system of proportional representation, the single-transferable vote.

ECONOMIST: This time it matters

Provocatively, the commission argued that the single transferable vote in multi-member seats, which is the Lib Dems' favoured system, should be used.

ECONOMIST: In one part of Britain a Liberal Democrat is in charge