Proposals by the UK Coalition government, which came into power in May 2010, to alter the electoral system for the Westminster Parliament have generated much debate and some controversy. The central plank of the campaigners for reform, viz. the introduction of a form of proportional representation, has been tried in New Zealand for some years now in the form of a mixed member proportional system. This article explains how that system came into being and how it has fared in the nearly two decades for which it has been in existence.