Party competition is an important mechanism for securing responsiveness and accountability in local government. Two measures of competition are identified and applied to all local party systems in England: dominance, which refers to the strength of the ruling party in the present; and volatility, which concerns changes in party strength in the past. The evidence shows that, on either measure, competition is strongest in the non-metropolitan counties and weakest in the London boroughs and metropolitan districts. By contrast, the two measures yield contradictory longitudinal results on the extent of competition: dominance has generally declined, but so has volatility. Thus conclusions on temporal trends in competition depend on the relative effects of dominance and volatility on local politicians' behaviour.