There is little space for third parties in a two-party system. The Liberal Democrat party, the UK’s third political bloc, is usually confined to brief cameo roles. But now, as the ruling Labour party crumbles, they believe they have a chance to seize centre-stage.

Nick Clegg, the leader of the Liberal Democrats, has said that it is “not beyond the realms of possibility” that his party could move into second place at the next election, ahead of Labour. His party might well receive more votes than Labour; they nearly managed that feat in 1983.