There are two essential facts that every single Labour supporter must grasp about the few days until the election:

1. In 2017, more than one third of all Labour voters only made up their minds to vote Labour in the last week of the campaign.

2. In 2017, face-to-face conversations were second only to the leadership debates in determining people’s voting decisions.

Put these two together, and every conversation over the next week matters. Paul Hilder at number-crunchers Datapraxis estimates that there are 150,000 votes at stake across 60 marginal seats that will now determine the election. Huge numbers remain undecided. Reaching enough of them to make a difference is an achievable goal in the time we have.

And we know that Labour’s army of canvassers is vastly larger than anything any other party can bring to bear. There have been extraordinary numbers out – and not just in the high-profile fights, like Faiza Shaheen against Iain Duncan Smith in Chingford. Wednesday evening saw 100 out in Hendon, the second most marginal seat in London, with a Tory majority of just over 1,000. The same thing has been happening in close fights across the country, with the data operation needed to get the right people in the right places having sharpened in the last two years. MyCampaignMap has had 2m page views at the time of writing, up hugely on the 2017 total – and there have been over 26,000 different campaigning events listed on the site. This is a social movement in action.

We know the so-called air war is brutal: the media treatment of Labour in general (and Jeremy in particular) during this campaign has, even by the standards of the last four years – even by the standards of the last election – been unrelentingly hostile. This noise will get worse over the next week. And most of it won’t even be seen or heard by most of us. The Tories have briefed their press that they intend to launch a “last-minute social media advertising blitz”, repeating the apparently successful so-called “Waterloo” strategy of Vote Leave during the EU referendum. Far from even the minimal scrutiny the conventional media provides, the Tories will be seeking to push an unremittingly negative message. They have offered a flimsy manifesto, containing little more than a promise of a hard Brexit – and a few morsels of hard-right red meat.

There are three reasons the Conservatives are behaving like this.

The first is that the foundations of British society are shifting against them. Look at the experience of the generation that has entered the labour market since 2008: falling wages, insecure work, little hope of a career, next to no hope of owning a home. Whilst a minority have escaped this experience, the majority of younger people in work have not. The basis of popular support for Conservatism is being eroded because our middle class is being eroded. The Tories cannot make a straight appeal to traditional Tory values in the way that, say, Margaret Thatcher once could.

The second reason is their record in office over the last 10 years. At any point in this campaign, from TV debates to local hustings, Tories confronted with the near-decade of their misrule – record homelessness, NHS hospitals flooded with sewage – come off worse. For that slightly older generation of voters in their thirties and forties, it is the distinctive experience of seeing their children shoved into underfunded and overcrowded schools; the shift from Tory to Labour amongst this age group in 2017 was striking. So the Tories cannot allow themselves to be tainted with their own actions. This record is why Boris Johnson will sit down for an interview with Gordon the Gopher’s old sidekick, but has now refused to do the same with Andrew Neil – or Julie Etchingham. Cowardice is integral to the Tories’ election plan.

The final reason is connected and it is the most visceral. It is fear. The Conservatives have never, in 40 years, been able to secure solid popular consent for the hardline programme most of the Cabinet are now signed up to. They could never push through the carve-up of the NHS that their Brexit plans contain if they had to win popular consent for it. They know this; if they didn’t realise it before 2017, they realise it now. They are frightened, but they realise being frightened can be made to work for them. They will get their 40% not by being honest about what they do want to do, but by lying about things Labour do not. The sheer volume of lies and misinformation offered by the Conservatives during this election is unprecedented. And where fear does not work, the relentless, overwhelming negativity of their campaign can cut with the lived experience of the last decade – perhaps the last 40 years – where for much of the country the slow grind of things steadily and visibly becoming worse means too many of us can never imagine it getting any better.

That is what Labour and the movement is up against for the last few days. Lies, fear, and despair, weaponised in service of a political establishment that, if it can think about the future at all, can only envisage more of the same forever.

There are three priorities over the next few days for all those who want to see a different future:

First, every conversation counts, and every conversation in a marginal seat counts most of all. Do everything possible to have those conversations. Find your nearest marginal, join the canvassing operation. Undecided voters are key, but so are those wavering and persuadable.

Second, those conversations can centre on the necessity of defending the NHS, but move on to Labour’s plans to tax the richest and big business to pay for meaningful improvements in everyone’s lives, from free childcare to WASPI justice. Challenge the Tory Brexit lies where they can be challenged.

Third, maximising turnout on election day itself is critical. In 2017, Labour lost seats where turnout did not rise by as much as the national average. Momentum’s MyPollingDay.com can tell you where, nearest to you, you can make the most difference on the day. Take the day off to make that difference. The stakes are terrifyingly high. But the future is unwritten.

James Meadway is a Novara Media columnist and former advisor to the shadow chancellor, John McDonnell.