It was a sickening moment. Many of the Labour supporters who had battled the wind and rain all day to get the vote out, in our heart of hearts, expected the worst. But the worst turned out to be even more terrible than we could have imagined.

The unprecedented army of mostly young activists who turned out day after day to knock on doors will be left reeling and disorientated. There’s a serious risk that this result will be for them what the Iraq war was for my generation. We turned out on the streets in our hundreds of thousands, we felt the intoxicating power of collective action … and then we lost. The sense of powerlessness and disengagement that followed was overwhelming. If anything, this result is an even more visceral punch in the gut. To be ignored by an arrogant prime minister is arguably a less bitter pill to swallow than to lose so catastrophically at the ballot box.

So where do we go from here? Firstly, we must beware of easy answers. Too many people will be lining up to offer explanations for Labour’s defeat that conveniently confirm everything they already thought. The right will blame Jeremy Corbyn’s radicalism and propose a lurch back to a vanished ‘centre-ground’ - but this is simply not a credible diagnosis given the woeful showing of the Lib Dems and Change UK.

In response, the Corbynite left may be tempted to shove all the blame onto Brexit. This at least has the merit of being partly true: it now seems clear that maintaining an electoral coalition that straddled the Brexit divide became an impossible tightrope for Labour to walk. But it is not the whole story. Anyone who has knocked doors for Labour in this election will have heard the words, ‘I’ve always voted Labour but I just can’t vote for Corbyn’. To pretend otherwise is pointless: it will convince nobody and does our movement a disservice. The question is why people felt this way - and how the left can nurture future leadership figures that inspire trust in spite of the inevitable attacks from the media.

Secondly, we do not have the luxury of despair. This result will have devastating consequences for the most marginalised, from migrants and people of colour to the disabled and homeless. It is vital that we stand shoulder to shoulder with them. And one of the few positives of this election has been the left’s ability to force Johnson’s hand on issues from public investment to a Trump trade deal on the NHS. This is a role the movement can and must continue to play in opposition. The result does not negate the experience of collective care and determination that many activists have found in the course of the campaign. Indeed, it is exactly that spirit we will need to take forward if we are to do what is needed in the months and years to come.

More fundamentally, this moment differs from my generation’s “Iraq moment” in one crucial respect. Iraq was an event, a single decision point that once lost was lost forever. The fight of today’s grassroots Labour movement is the fight to replace a visibly crumbling status quo with a new social and economic settlement. This fight was never only about Corbyn - he was simply the lightning rod that channelled the rage and hope of a generation into the Labour Party. Indeed, the almost accidental nature of his rise to power perhaps helps to explain why Corbyn was ultimately not the leadership figure who could take this project to electoral victory. But it does not end with his defeat.

Polling consistently shows that Labour’s policies for structural reform of the economy - from public ownership of the railways to workers on boards - are popular. There is certainly no serious evidence that they are to blame for this result. Indeed, part of the problem was that Labour did not tell a compelling story about the need for this transfer of power to the many, instead leading with a shopping list of spending pledges that seemed only to make voters disbelieving and disengaged. Ultimately, the problem was not that people did not want radical change but that Labour failed to inspire them to believe it was possible.

Thirdly, then, we must build on what we have. The level of grassroots mobilisation in this election has been truly phenomenal. In the end, it seems to have been largely overwhelmed by the national swing - but this may mask its significance and potential. Turning on the likes of Momentum would be exactly the wrong response. Instead, the question should be how to strengthen the movement’s roots in working class communities, not just at election time but all year round, and how to expand Labour’s activist base beyond the mostly young, white and middle class. Likewise, in the past two years the Labour Party has been the home of more serious, creative thinking about how to build a new economy and society than I have seen anywhere in my lifetime. It would be a grave mistake to throw this work under the bus. Instead the task is to nurture and develop it, and chart a path towards making it politically possible.