Equalising votes but enabling bias: The electoral impact of the 1977 and 1999 ward boundary reviews in London

The boundaries of electoral units in Britain are periodically reviewed in order to enact the democratic principle of 'one person, one vote, one value'. The Commission-led reviews of local ward boundaries in London in the late 1970s and late 1990s both successfully reduced the variance in elector- councillor ratios within individual London boroughs and thereby helped to remove any bias in election outcomes stemming from malapportionment. However, other factors such as the efficiency with which a party's vote was distributed, the impact of differing levels of turnout and the intervention and success of third parties all remained crucial in determining the precise relationship between votes cast and seats won. It is impossible to ensure that all votes are equal under the 'first-past-the- post' system because these other components of electoral bias are either not subject to review, or amenable to manipulation.