UKIP’s rise has caught the establishment by surprise, with the main parties doing all they can to prevent the further rise of the right-wing populist party. However their success is likely to be limited by the difficulty that new parties have in breaking into a House of Commons distinguished by its continuing use of First Past the Post and a House of Lords which doesn’t hold elections at all. Stephen Barber argues that UKIP’s rise could spark unplanned constitutional reform to correct these undemocratic anomalies
