This fault line has remained in the Socialist party ever since, causing occasional tremors of disunity, such as the 1989 headscarf row, and the 2004 ban on religious symbols in schools. The attack on the offices of Charlie Hebdo in 2015 caused the ideological plates to shift again. On one side stands the satirical magazine’s supporters, like the former Socialist prime minister, Manuel Valls, and the philosopher Alain Finkielkraut; on the other, the ‘Islamo-gauchistes’, led by Edwy Plenel, the former editor of Le Monde, who believes that French Muslims are institutionally victimised and that those who criticise their religion – such as the author Michel Houellebecq – are guilty of Islamophobia.

Oxford professor Tariq Ramadan is the reason for this latest, and most virulent, row within the French left. Days after allegations of sexual assault were levelled at Ramadan, Charlie Hebdo depicted Ramadan on its front cover in a state of impressive arousal under the headline ‘The Sixth Pillar of Islam’. Plenel wasn’t amused and accused the magazine of waging ‘a war against Muslims’. Charlie Hebdo, which has received several death threats since the Ramadan cartoon, responded with a furious editorial, accusing Plenel of ‘condemning Charlie Hebdo to death a second time’. The next issue of the magazine featured Plenel on the front cover in a variation of the ‘see no evil, hear no evil, speak no evil’ monkey. Valls then waded into the dispute, saying that Plenel and his Islamo-gauchistes cohorts share an ‘intellectual complicity’ with Islamic extremism. The former PM is a long-standing adversary of Plenel, stretching back to 2013 when, as minister of the interior, he explained that he refused to use the word ‘Islamophobia’ because it was ‘a Salafist Trojan Horse’, a term invented to shut down any criticism of the religion.