Dear Jeremy Corbyn,

We are writing to you as fellow socialists and progressives to urge you to work with us for the future of our continent.

The left is resurgent across Europe; each of us sees this in our own movements, and in one another’s. Your Labour party, the breadth of its vision, the passion of its language, the strength of its membership, has brought inspiration and optimism to us all. Which we need, for the picture is not at all rosy. Fascism is on the rise within Europe, buoyed and supported, implicitly and explicitly, by an invigorated authoritarianism without. Corporate interests prevail, unchecked by a post-ideological politics which has exhausted itself. Climate change becomes climate crisis, and those who deny it become ever more forceful.

We all have deep misgivings about the dominant institutions of the European Union, and what they have become over the past three decades. The contagious creed of austerity has spread through its airways. The interests of capital and global corporations have come to take precedence over those of citizens. Despite more wealth than ever before, the disparities across the continent have fostered exploitation and insecurity. And despite the liberty and adventure that the EU has opened up, the deaths in the Mediterranean are evidence of the emergence of terrifying new and old prejudices and fears.

Yet we are not ready to surrender this once great project to those who would subvert it. To do so would betray its creators, whose values we cherish. More importantly, it would leave us weakened when we most need our strength, and isolated when we most need our solidarity. There is no answer to any of these questions that is not transnational. There is no way that our frustrated fellow citizens will feel represented unless they can be heard at European and global levels.

We need you in the EU. Nobody understands better what it takes – from the law, from the union movement, from activism – to bring to life and fruition the ambitions and dreams of every citizen. We need you, as you can become a catalyst for a different Europe, providing new and necessary momentum for true progressive change. We need one another, just as we needed one another at the inception of the EU, to meet the most urgent challenges mankind can ever face: to avoid war; to foster equality; to cooperate in the face of threats to our planet; to harness solidarity that it might achieve the most of which it is capable.

As your trades unions point out, it is usual in a negotiation that the final deal is taken back to the members. We would ask you to demand that the decision to trigger article 50 is revoked, in light of the recent opinion from the advocate general to the European court of justice, and allow the people’ s voice to be heard before Brexit becomes irreversible. We hope that the Labour party will spearhead such an initiative and join us in embarking on a programme of Europe-wide transformation.

In solidarity,

Signed: George Papandreou, president of the Socialist International; Udo Bullman MEP, president of Socialists & Democrats in the European Parliament;

Marc Tarabella MEP

Boris Zala MEP

PierAntonio Panzeri MEP

Ricardo Serrão Santos MEP

Elly Schlein MEP

Dimitris Papadimoulis MEP

Marita Cremascoli Hellner MEP

Eugen Freund MEP

Paul Tang MEP

Martina Werner MEP

Peter Kouroumbashev MEP

Dr Dietmar Köster MEP

Evelyne Gebhardt MEP

Petra Kammerevert MEP

Mercedes Bresso MEP

Arndt Kohn MEP

Péter Niedermüller MEP

Manuel Dos Santos MEP

Josefina Sanchez Moriano MEP

Josef Weidenholzer MEP

Tibor Szanyi MEP

Andrejs Mamikins MEP

Florent Marcellesi MEP

Vilija Blinkeviciute MEP

Albin Kurti, president of the Movement for Self-determination in Kosovo

Michele Emiliano, president-governor of the region of Puglia

Ihar Barysau, chairman of the Belarusian Social Democratic party

Aliaksey Sihayeu, first vice-chairman of BSDP

Volga Isaikina, deputy international secretary of BSDP

Elke Ferner, executive member of PES Women

Adrian Dohotaru, Romanian MP

Cecilia Gondard, PS France

Fitore Pacolli Dalipi, Kosovan MP

Fatmire Mullhaxha Kollcaku, Kosovan MP

Saranda Bogujevci, Kosovan MP

Arberie Nagavci, Kosovan MP

Valon Ramadani, Kosovan MP

Sami Kurteshi, Kosovan MP

Shemsi Syla, Kosovan MP

Drita Millaku, Kosovan MP

Ali Lajci, Kosovan MP

Sonja Licht, fund for political excellence, Belgrade

Milan Nikolic, sociologist, Belgrade

Matthew Corr, chair of SDLP Youth, Northern Ireland

Claudia Walther, SPE Delegate

Johannes Kup, PES activist

Fredy Fransen, safety adviser, Euratom

Bernd Lang MEP

Tiemo Woelken MEP

Rhonda Donaghey, Labour Women of Ireland

Marie Arena MEP

João Albuquerque, president of the Young European Socialists

Euclid Tsakalotos, minister of finance of Greece

Doriano Dragoni, project leader, Global Progressive Forum

Arne Lietz MEP

Jo Leinen MEP

Ana Gomes MEP

Juan Fernando Lopez Aguilar MEP

Maria Noichl MEP

Zita Gurmai, MSZP Hungary and president of PES Women

Aleksander Sulejewicz, associate professor of economics at the Warsaw School of Economics

Francisco Assis MEP

Corinne Narassiguin, PS France

Dan Baron Cohen, playwright, community theatre director, cultural theorist and arts educator

Dirceu Ten Caten, PT MP-Pará, Brasil

Frauke Borst, adviser to SPD

Mario Bova, Italian former ambassador to Japan and director general for European affairs

Gian Giacomo Migone, former chair of Italian senate foreign relations committee

Tana De Zulueta, former progressive senator, Italy

Erkki Tuomioja, former Finnish foreign minister

Álvaro de Vasconceles, former director of the EU Institute for Security Studies

Pedro Bacelar de Vasconcelos, Portuguese Socialist party MP

Luciana Castellina, journalist, politician, activist and candidate for Italian president

Pierre Schori, politician and diplomat, Sweden

•This article was amended on 10 December 2018. A previous version omitted several names from the list of signatories. This has been corrected.