
Jeremy Corbyn has never been an enthusiast for the EU. He voted against EEC membership in the 1975 referendum, the Maastricht Treaty in 1993 and the Lisbon Treaty in 2008. For decades, he stood in the left sovereignist tradition exemplified by Tony Benn. As recently as last summer, during the Labour leadership contest, he told the New Statesman that he had not “closed his mind” to EU withdrawal.
Why he eventually sided with In remains something of a mystery. Was it a principled decision? Or did the weight of EU support among the shadow cabinet, the PLP and Labour members convince him that there was no alternative? Whatever the ultimate cause, he came off the fence just four days after becoming leader last September.