In 2013 the Left in Britain was thinking of Greece. That year, a ragtag coalition of Trotskyists and obscure communist splinter groups set up Left Unity, a party hailed by its activists as the British equivalent to Syriza. According to Andrew Murray, a senior figure in the trade union Unite and later an adviser to Jeremy Corbyn, Left Unity would inevitably fail because working-class voters in the UK remained deeply wedded to the Labour Party. “The British working class will support a ‘British Syriza’ when they regard the British Labour Party in the same way as the Greek working class regards PASOK. That is not where we are at present,” Murray wrote.

In the event, Murray was proven right. Less than two years later, in 2015, Left Unity gained a national total of 455 votes in a general election that saw the Liberal-Conservative coalition replaced by a small Conservative majority. The attempt at a British Syriza won less than half the votes of the pop-up party fronted by Bez, the maraca-wielding dancer from the Happy Mondays. For its part, despite a small favorable swing in the popular vote, Labour lost twenty-six of its MPs. The day after the election, Ed Miliband resigned as Labour’s leader — yet even the prescient Andrew Murray failed to predict what would happen next.

Unlike elsewhere in Europe, which has seen a surge of new left-wing parties in the 2010s, in the UK some of those same radical forces erupted within the 120-year-old Labour Party. As a skeptic of Left Unity’s chances might have pointed out, Britain’s electoral system is a decisive factor in explaining Labour’s persistent appeal. This first-past-the-post system based on geographical constituencies punishes smaller parties who are unable to accrue the most votes in any particular area. This also helps us understand why fiercely opposed political perspectives have historically inhabited Labour, typically referred to as a “broad church.”