The open letter calls on Von der Leyen to “reject any normalisation, cooperation or alliance with the far right and radical parties” and denounces a physical assault on German centre-left politician Matthias Ecke. Ecke was “seriously injured” after allegedly being attacked by four young men while putting up campaign posters.

The letter has been signed by five of the main political parties in the European parliament including the Socialists & Democrats, Renew representing the liberals, the Greens and The Left.

But the European People’s Party (EPP), the largest group in the parliament, representing conservative-leaning parties throughout Europe, declined.

French MEP Valérie Hayer, head of Renew, said her group, which is backed by Emmanuel Macron, regretted that the EPP had not signed. “This puts their commitment to the common fight against destructive, far right forces into question. We urge the EPP to reconsider and to join this pro-European commitment,” she said.