This weekend the UK Independence party (Ukip) will enter a new stage in its strategic evolution. In a television broadcast the party, already the most successful challenger to the main parties in postwar English politics, will launch an invasion of Labour's working-class heartlands. With a growing war chest, Ukip plans to take its message direct to blue-collar communities in red territory. The idea, Leader Nigel Farage has explained, is not complex: "Gun for Labour".
At first glance, this seems bizarre. Conventional wisdom holds that the rise of Ukip has come at the expense of Cameron's Conservatives. So why go after Labour? The reasons are twofold.
First, for some time the so-called clowns of British politics have been pointing to vulnerabilities within the Labour base. One member of their high command told us: "The low-hanging fruit for us are not former Tories, but people who have traditionally and culturally always been Labour."