The Cost of Conviction in British Politics : What Happens to Labour's Majority If the Party Moves Back to the Left?

The proximity theory of voting states that people support the party that they perceive to be closest to their own positions in the dominant issue space, a space that is typically best represented by a unidimensional, left-right continuum. In this paper, a probabilistic modified proximity model (PM2) of British voting is constructed and calibrated against recent British opinion polls of voter and party position and declared voting intention. It modifies the standard proximity theory to say that voters will not vote for a party more than a critical distance away on the left-right continuum, and that a proportion of potential Lib Dem voters do not believe that they are ready for government, and so either do not vote, or vote for the nearest alternative party instead. Results from PM2 show that Labour could increase its mean lead over the nearest opposition slightly by continuing to move to the right a little beyond Tony Blair's present position. Moving back to the left, to a position represented by Gordon Brown and Labour MPs as a whole, would reduce Labour's overall majority by a mean of 133 seats (90% confidence interval a reduction in overall majority of 84 to 168 seats), giving a 14% chance of Labour not obtaining an overall majority, if the voters do not change their views and the other parties do not change their positions. Moving to a triangulation position, which is a compromise between conviction and expediency, would reduce Labour's overall majority by a mean of 62 seats (90% confidence interval a reduction in overall majority of 14 to 118 seats). Only in the very worst cases would this lead to Labour's overall majority disappearing with the proviso, as before, that the voters do not change their views and the other parties do not change their positions. Reducing the proportion of Lib Dem voters who feel they are unready for government, or a move back towards the centre by the Tories, could cause significant electoral problems for Labour. All of the results are based upon the proximity theory of voting, which is only one amongst several theories of electoral choice, and should be treated with the appropriate level of caution that this implies