GREEK words loom large in politics, although some are better-known than others. Most people recognise the term “democracy”. “Politics” itself has Greek origins. Fewer people would be familiar with “Pasokification”—unless they are a member of the Labour Party.

Pasok, a struggling centre-left party from Greece, is surprisingly prominent in the minds of Labour activists. Where once the Greek party commanded the support of 44% of voters, a stint in government overseeing brutal spending cuts saw this figure dribble to 5% by 2015. Naturally, Labour wants to avoid this fate, dubbed Pasokification. So the Greek party has become a cautionary tale cited by Labour activists urging their leaders to maintain opposition to Tory austerity. Fear of the Pasokification of Labour boosted the far-left Jeremy Corbyn during his successful tilt at the Labour leadership in 2015, recall those who worked on his campaign.

It was another Greek party that Mr Corbyn’s supporters wanted to emulate. Syriza, the radical left-wing party with a charismatic leader, Alexis Tsipras, promised to roll back austerity in the Aegean, while successfully navigating complicated bail-out negotiations in Brussels. Across Europe, centre-left parties had gone the way of Pasok, with voters deserting them, often for the far-right. For Corbynistas, Syriza provided a rare blueprint for a successful left-wing party when it was elected in 2015.

Three years on, however, Syriza now serves as another warning to some on the left. The parable of Mr Tsipras’s eventual capitulation—his radical government brought to heel by capital markets and an intransigent European Union—is seeping into the left’s consciousness. Support for the Syriza government has dwindled in Greece. Former members accuse the leadership of treachery. “The left loves a good betrayal,” says Joe Guinan, a fellow at the Democracy Collaborative, an American think-tank. After Labour’s better-than-expected result in last year’s general election, fears of Pasokification have been placated. Now some Labour activists wonder if, in office, it could fall victim to Syrizification.

In front of some audiences, John McDonnell, the shadow chancellor, implies that he would not capitulate to the forces of capital without a scrap. Speaking to activists last year, he casually mentioned that Labour had been “war-gaming” events such as a run on the pound, in the event that the party made it to Downing Street. “It tries to answer the question about what happens when or if they [the establishment] come for us,” he said (incidentally while on a panel with a Syriza MP).

Yet Mr McDonnell has also shown a willingness to bend his views, launching a charm offensive in the City. One proposal discussed this month by Labour bigwigs involves souping up the Bank of England, giving it a target to boost productivity and allowing it to comment on fiscal policy. Empowering technocrats jars with other parts of Labour’s economic programme, which aims to “democratise” the economy.

The party leadership seems willing to compromise for a shot at power. But fears of Syrizification, when a left-wing party surrenders its radicalism, means some Labour activists may be unwilling to do so.