Of all the experiences Jeremy Corbyn has endured since becoming Labour leader, delivering speeches in favour of the European Union must rank among the strangest. Until the referendum campaign, almost every word that Corbyn had spoken about the EU had been critical. In the Bennite tradition, he voted against EEC membership in 1975, against the Maastricht Treaty in 1992 and against the Lisbon Treaty in 2008. Though he never advocated withdrawal (at least partly because the question did not arise), he was agnostic about Brexit as recently as last summer.

Corbyn is now a convinced Remainer (as those shadow cabinet ministers who have probed him confirm) but he has rarely hidden his lack of enthusiasm for the EU. Though his enduring scepticism mirrors that of the public, Labour MPs have long feared that his apathy could result in a Leave vote (privately vowing to launch a leadership challenge in the event of Brexit). But at the party's final EU rally, in the impeccably Remain surroundings of Granary Square (opposite Waitrose no less), Corbyn delivered something close to a passionate case for membership. "Vote for jobs! Vote for rights at work! Vote for our NHS! Vote to Remain in the European Union," he cried.

But this being Corbyn, his speech soon took a far more idiosyncratic turn. Country-by-country tax reporting, a financial transaction tax, zero-hour contracts, and the Posted Workers' Directive ("absolutely nothing to do with the post office") were the subjects that truly roused him. These issues are not, to put it mildly, the talk of swing voters. But they are true to Corbyn's socialist soul. His speech was not a case for the EU of today but for that of tomorrow. The Labour leader aspires to build a "Europe of solidarity" capable of remedying the the maladies he diagnosed. He spoke excitedly of the "stream of messages" he had received from "trade unions, socialist parties and many others" urging him to work for reform. He ended with the words with which he closed his leadership acceptance speech: "Things can, and they will, change".

Many on the Labour side would have preferred a more conventional account of the economic risks of leaving (a subject with which Corbyn has little engaged), not least because the party is no position to deliver reform. But having agreed to make a case for the EU, Corbyn was only ever going to do so in his own way. Labour, a europhile party led by a eurosceptic, can now only wait to find out whether it has been enough.