Labour supporters should never have doubted Jeremy Corbyn – this must mark the end of Blairite centrism for good

With all the usual caveats, the exit polls have spoken and they have sent us into excited shock. It has already been described as the most sensational exit prediction that people can recall: if the exit figures are to be believed, Labour’s vote is up and has risen by more than the Conservative vote. If correct, Labour has climbed 34 seats to 266 – putting some kind of victory in sight. Spare a thought for those at Conservative HQ right now.

Speaking to Sky News earlier, film director Ken Loach summed up his view on what lies behind this extraordinary exit poll – the rise of Jeremy Corbyn set against Theresa May’s waning appeal: “People have recognised an authentic man of principle, as opposed to someone who is acting like a robot.” For all the naysayers that underestimated Corbyn, casting him as incompetent, while mocking his suits and dismissing his politics – well, just take a look at that poll.

Of course it’s only a projection and there’s a long night ahead of us. But whatever happens, few could deny the Labour leadership has run an extraordinary campaign: vibrant, engaged, modern and inspiring, it frequently caught the Conservatives on the defensive and make May’s operation look stale, creaky and just a bit cranky.

Even the most hostile of Labour leader Jeremy Corbyn’s opponents cannot now ignore that he has performed incredibly well against the odds, confounding expectations. The more the public saw of him, the better his personal ratings: his sincere and easy manner coupled with confident media appearances made him look increasingly prime ministerial as the campaign progressed. And those giant crowds that rallied to his stump speeches must have driven Conservatives crazy – certain in the knowledge that the standoffish, people-averse Theresa May simply couldn’t compete with such inspiring visuals.

The party manifesto, meanwhile, presented a real choice to voters, ending the years of Labour’s triangulated centrist politics – a state of affairs that many thought accounted for the party’s steady decline. This manifesto’s popular polling should really put an end to the endless discussions of how Labour should get its game back. Because it turns out– who knew? – that real left-wing politics, premised on investing in the economy and the welfare state, tackling rampant inequalities, banishing avoidable poverty and creating a fairer society are popular with a British public that’s straining after years of economic crash, austerity and neglect.

A solid left manifesto cuts through public disengagement, with demonstrable proof that not all politicians are the same, that voting can make a difference. It gives those who pound the streets for the party something credible, a vision of an alternative society, to discuss with voters. It fires up young voters who feel that politics has simply given up on them. And it brings ex-voters back into the fold – not just Labour voters of old, but Greens and Liberal Democrats.

Significantly, campaigners report that the party’s offer, in particular on renationalisation, national investment and taxing the 5 per cent, was beginning to wean Ukip voters off a potential new Tory-voting habit and bring them into Labour’s patch. The party’s surge in the polls is in no small part down to its left policies – which should mark the end of Blairist centrism for the party.

Corbyn’s leadership has made socialism a mainstream prospect again. And in this context it is, frankly, ludicrous to suggest that anyone else at the party’s helm would have fared better in this election: for who, other than the Corbyn leadership, would have put forward such a bold manifesto?

On top of which, this party galvanised its 500,000-strong membership into campaigning and canvassing for votes. Momentum, the grassroots group of Corbyn supporters, sent scores of activists into marginal seats across the country – the organisation and innovation of such efforts has brought many into politics for the first time and has stunned constituency parties with the levels of solid, practical help suddenly on offer.

Most of all, Corbyn’s Labour party has brought hope back into politics. That’s something that cynics scoff at – because the hope felt by progressives is so often crushed by a political reality moving ever rightwards, so what even is the point?

Well, whatever happens tonight: the point is the long game. Because social transformation is slow and starts on the streets and in communities, fighting local causes and defending the vulnerable; building a credible, reliable movement from the bottom up.

When there’s a true left-wing party in parliament that acts as a lightning rod, firing up political support and energising movements on the ground – that’s when the left as a political force rebuilds, reinforces and regains power. And that’s why, whoever wins this election, the Labour party has to keep to the left.