In recent years, it has become painfully common to read about the “crisis” facing social democracy. Across Europe, social-democratic parties have slipped to historic lows in polls and election results, often losing their status as major players in their countries’ politics in the process.

Nowhere is this story truer than in Germany, the original home of social democracy. After polling consistently over 40 per cent in the 1970s and 1990s, the Social-Democratic Party of Germany (SPD) scored barely 20 per cent at the last election in 2017. It has since sunk to below 15 per cent in the polls, prompting the talking-point that the party is now the least popular it has been since Friedrich Engels was a member.

Efforts by the party to overcome its current weakness have had little effect. Neither the leaderships of Martin Schulz, former president of the European Parliament, nor Andrea Nahles, a prominent voice on the SPD’s left wing, have proved able to reverse the party’s decline.

This has led party members to look abroad for inspiration, especially to the UK, where the Labour Party has largely bucked the trend of social-democratic decline. Kevin Kühnert, leader of the SPD’s “JuSo” youth wing, has been especially attuned to developments on the British left, and has been explicit about the party’s need to learn from the “traditional political answers” Labour has offered under the leadership of Jeremy Corbyn – particularly its unabashed commitment to the resurrection of “socialist democracy”.

Kühnert’s Anglophile strategy has rich historical precedent. In the 1890s, Eduard Bernstein, the grandfather of German social democracy, was so influenced by the Fabian Society that his SPD colleagues accused him of seeing the world through “English spectacles”. After the First World War, Weimar Germany’s socialist periodicals – Neue Zeit, Gesellschaft, Sozialistische Monatshefte – regularly featured articles by major figures on the British left: Clement Attlee, Ramsay MacDonald, G.D.H. Cole, John Maynard Keynes.

So what can the German left learn from Corbyn’s transformation of the Labour Party? Perhaps the greatest lesson is that “same old, same old” neoliberalism – remorseless privatisation, financialisation, austerity, deregulation, and a shrinking state – has become, for the left, a losing game. Labour under Tony Blair, Gordon Brown, and Ed Miliband became a pale echo of the party’s rich progressive tradition – to put it unkindly, “Toryism with a human face”. Likewise, the SPD suffered immeasurably from cleaving to the stale doctrines of the Gerhard Schröder years, to which it shackled itself through a total of ten years of grand coalition with Angela Merkel’s CDU since 2005.

Instead, like Corbyn’s Labour, the SPD needs to craft a new ideology – one that carefully balances looking back to before neoliberalism, and looking forward, beyond it. It needs a vision that does not try to fix the status quo, but to replace it: it needs, in short, to embrace anti-capitalism in a meaningful way.

The German left must also learn from the success of Momentum – an activist organisation that started by focusing on one issue, then gradually expanded its mission to push for greater change. For Momentum, that issue was ensuring Corbyn’s election as leader. For the German left, the likeliest candidate is Kühnert’s 2018 “NoGroKo” campaign against the grand coalition. The SPD’s electoral weakness has borne out Kühnert’s arguments against its participation in government – and the German left need to mobilise around this issue, focusing on taking the SPD into opposition, where it has the breathing room to achieve meaningful ideological renewal.

But above all, the SPD must learn the rewards of keeping the left united, across parties and among the electorate. The signal marker of Labour strategy under Corbyn has been to preserve the alliance between the post-industrial working class and metropolitan university graduates. This has meant doubling down on what these groups agree on (welfare, healthcare, housing) while carefully negotiating – with studied vagueness – what they do not (Brexit, trade, immigration). The result has been the formation of a credible left opposition force in Britain for the first time in nearly 40 years.

Yet while Labour is still a united party, the German left is split. In the 1990s and 2000s, the SPD failed to absorb – even rejected – the various post-communist left currents that coalesced in 2007 into Die Linke, a party that has spent most of the last decade resolutely locked at 9-10 per cent in the polls. Divisions over East Germany’s legacy and repeated state surveillance scandals have merely been the latest grim chapter in the fraught history of fragmentation on the German left; yet they have not prevented the formation of “red-red” SPD-Die Linke coalitions at the state level.

Ultimately, the SPD must accept that its future does not lie in eternal coalitions with the CDU, but with the left around Die Linke. Given its parlous electoral state, the SPD must abandon its path-dependent centrism and open the door to pursuing red-red strategy at the national level, in order to bring about the ideological reinvention, strategic alignment, and eventual reunification of German social democracy.

Dr Marius S. Ostrowski is an examination fellow in politics at All Souls College, Oxford.