No unnamed Labour source can mask what’s happened, and no professional Corbyn-sceptics can derail it. There is now a real prospect of another referendum. Labour has committed to several parliamentary manoeuvres including one final stab at its own Brexit, which will certainly fail; another to support Yvette Cooper’s attempt to push no deal further into the realm of destructive fantasy, where it belongs; and a vote on an amendment demanding that any Brexit deal approved by the Commons must be ratified in a public referendum. In that public vote, Labour will campaign to remain in the EU.

“Sources” within Labour continue to deny this new reality, even as its senior frontbenchers have announced it. “It’s a disgrace,” one told me, “that unelected, unsourced voices are briefing against Labour’s frontbench.” “If they want to speak for the Labour party,” a staffer said, “they should stand for the Labour party.” The position as it stands now is not the seismic shift some suggest. It is a continuation of the policy adopted at Labour’s party conference last September. And credit for it belongs with the grassroots of the Labour party.

Wouldn’t it be inspiring to put these tired, abstract, 60s arguments behind us and concentrate on things that matter?

Jeremy Corbyn’s Euroscepticism has always been overplayed, and absurdly so: this supposedly committed Bennite is a keen supporter of the single market, the core element of transnational cooperation that Tony Benn actually objected to. But more importantly, if you want to understand why so many predictions were wrong, Corbyn’s determination for democratic renewal has been underplayed, to the point of being ignored. The desire to reconnect meaningful levers between the party and its members has always been far more salient to his politics than any old guff about socialism in one country.

This isn’t to say there aren’t influential leavers around the leadership, and without Keir Starmer’s determination to stick to both the letter and spirit of September’s conference motion, this may not have been the outcome. Key unions – the TSSA and, lately, the GMB – were significant. Organisations such as Another Europe is Possible and Remain Labour did the legwork of amassing 150 motions on Brexit to take to conference in the first place. Anyone could have lost confidence in the nation’s appetite for remain, without data from Hope Not Hate and Best For Britain. And that ongoing tension many members felt, between despising Brexit as a manifestly far-right project, and wanting to maintain loyalty to a leader whose own preference was endlessly interpreted but often unclear, was bridged by Momentum. It was highly ambivalent on Europe but ultimately, also, more committed to party democracy than to a position on any single issue.

Yet this new context in which we find ourselves, a real prospect of a public vote to swim out of this godforsaken Tory swamp, is a triumph of Labour members.

This is important not because of any crowning determination to see credit situated where it is due – rather than ascribed, wildly, to the Independent Group. Rather, because if you want to actually know what a ratification vote would look like, and the remain campaign within it, this is no sudden scramble to put together some arguments and hope they’re different enough to the self-interested status quoism of the Stronger In campaign of 2016. Labour’s members have been working on a strategy for two years.

The arguments split three ways: what does remain and reform actually mean, in terms of our relationship with the EU, and our hopes for the continent? What were the real problems unmasked by the referendum result, and what would it take to solve them? And finally, wouldn’t it be inspiring to put these tired, abstract, 60s arguments behind us and concentrate on things that matter?

The left in Europe need us, and we need them. We need one another to create the first carbon-free continent, and fast. We need to fight the rise of the far right together, for so many obvious reasons, not least the paradox that violent ethno-nationalists are working tirelessly across borders to cooperate with one another, and no single nation can meet that threat working alone. We need a transnational union movement, a financial transaction tax, an enforceable floor for corporation tax between countries; we need an entire constellation of cooperative measures so that no multinational can get its fingers burned over poor working conditions in Munich and immediately move to Kraków, or Stoke.

We need to defend such laws and regulations as were co-created along humane and social principles, and unpick the elements of the Lisbon treaty that sought to detach the market from democratic forces and regulatory oversight. The only progressive European voice I have ever heard supporting Brexit did so on the grounds that the UK was so often the impediment to action on climate, or on workers’ rights, that the continent would be better off without us. If we have any ambitions of our own as a force for renewal, or any sense of solidarity in reforming a European project whose negative elements we partly created, we cannot accept that.

“Fix Britain instead” was the slogan for a second referendum suggested by Tom Kibasi, the head of the IPPR thinktank. Its Prosperity and Justice inquiry last year drew together a set of realities that would be enough to make anybody angry: pathetic wage growth, housing inequality, income inequality, wealth inequality, high household debt, weak government investment, poor research and development, and a tax system that doesn’t meet the needs of public services or the demands of social justice. None of this was driven by EU membership. All of it is more pressing, more meaningful and more within our grasp than any change to our relationship with the EU, which we have seen not just de-prioritise but obliterate the national agenda.

There is some overlap between the third argument – let’s move on – and the first two, yet it warrants its own category, because the appetite for it is just so strong: the almost unbearable lightness of being able to say no to more of this bilge; no more colonial fantasists; no more throwbacks invoking fake passions about the second world war; no more feckless aristocrats flapping their hands and saying, “It’s fine for that factory to close, manufacturing is so last century and besides, it would have closed anyway”; no more nonsense about superiority and dominance and prowess, while trade deals unravel before they’ve even been stitched; no more chancers taking crash courses in French geography, or Irish history or Chinese diplomacy in real time. Let’s just move on, and talk about things that are real. This is how a remain campaign will be fought, and this is how it will be won.

• Zoe Williams is a Guardian columnist