The UK Independence Party (Ukip) is the most significant new force in British politics for a generation. Under the leadership of Nigel Farage, the party has enjoyed a remarkable rise, winning the 2014 European Parliament elections as well as two parliamentary by-elections, and attracting mainstream defectors to achieve major party status. By the time of the 2015 general election, Farage and Ukip stood on the threshold of becoming a major force at...