ANDY BURNHAM’S barely veiled threat that the Labour leadership result could be “open to legal challenge” is the latest evidence that Jeremy Corbyn is on course to win.

This is now the consensus in the media too. It seems a lifetime ago that our parliamentary reporter Luke James was lurking in the corridors of Parliament, pouncing on MPs who had offered to nominate Jeremy if he looked like getting on the ballot and asking them to make good their promises.

This is no time for complacency — the Corbyn campaign needs every vote — but the debate is shifting from whether he will win to what happens when he does.

On the right, figures such as Boris Johnson declare that the Tories can’t believe their luck. Labour will elect the “unelectable” Corbyn and the Conservatives reign forever.

The same assumption dominates most of the New Labour attempts to “rugby tackle” Corbyn before he reaches the finish line. It was the sole binding narrative of Gordon Brown’s interminable list of heroic figures from the past who would supposedly have plumped for one of the “centrist” candidates in this election if they were still alive — as if Keir Hardie or Nelson Mandela would have responded to setbacks by adopting the policies and language of the enemy.

It doesn’t hold up. As Jon Trickett told the New Statesman, “nobody’s actually bothered to set out the case in detail to show he can’t win” an election.

Like the many “unelectable” Corbyn policies which are actually backed by the public, from public ownership of the utilities and transport to opposing Trident, the idea that Corbyn would himself be a turn-off at the ballot box is a media myth.

It’s rooted in the idea that May’s general election saw Britain give a massive thumbs-up to the Conservative Party, and therefore that the public have shifted to the right.

But when the number of people who didn’t vote at all is so much higher than the number who voted for the winning party — 34 per cent of the electorate compared to 24 per cent — the truth is more complicated.

A gradual decline in the number of people voting — it has not hit 70 per cent since 1997 — demonstrates the gulf between rulers and ruled in this country. To use the terminology of the liberals, the governing are losing the consent of the governed. This was a problem under Labour too, and is usually labelled “voter apathy,” as if it’s down to laziness. Actually people who opt out of the political process generally do so because they can’t see what it achieves.

The immense surge of support for Corbyn — the packed-out rallies, the hundreds of thousands of new Labour supporters — has done more than confuse and infuriate the Blairite old guard.

It’s motivated by hope — that Britain can become a different and better country. Hope has been in short supply in my political lifetime. This isn’t simply the personal gripe of a socialist who has never seen a socialist government, but embraces the narratives of the Labour and Conservative parties alike.

Secure, long-term jobs, final-salary pensions, affordable good-quality housing, higher education funded by the state — all are becoming things of the past. Young people are told that life will be harder for them than it was for their parents — that what was somehow affordable in the much poorer Britain of the 1940s is no longer affordable now.

When the political class is in agreement on all that, the logical response is disengagement. This is why the other candidates are incapable of leading a Labour resurgence — despite hints from the Guardian and New Statesman, which both back Yvette Cooper, that she could still take over the party in the event of Corbyn’s (inevitable, it is hinted) removal before 2020.

Similar noises have come from Cooper’s own team. In a bizarre outburst, Liam Byrne — he whose “no money left” gag proved so useful to the Tories over the last parliament — attacked Burnham, arguing that he could never unite the party since he was prepared to give Corbyn a senior job if he won.

Put aside Byrne’s absurd contention that the only way to unite the Labour Party is to refuse to work with the most popular candidate, and even for the moment his hint in the same diatribe that Labour should back air strikes on Syria.

He is unfortunately correct that there are those in the parliamentary party who will do their best to lead revolts against Corbyn every time a contentious issue comes up. Him, for instance.

Corbyn has already made clear that the Labour Party will become more democratic if he wins, and the voices of ordinary members up and down the country will count for more — but it doesn’t mean the large number of Labour MPs who abandoned socialism long ago will lose their capacity to cause trouble.

In that they’ll be backed by the media. Of British dailies, only the Morning Star has backed Jeremy Corbyn. Other papers have been happy to smear, ridicule and undermine him, something that will intensify if he becomes party leader.

Promoting the positive policies and transformational potential of a Corbyn-led government will require strengthening the alternatives to the monopoly press — both by increasing this newspaper’s circulation and by maximum use of social media and the internet, as well as through pressure on broadcasters.

It will mean maintaining the political momentum of this summer’s campaign and building on it over the coming years. There has been much talk from all the candidates in this contest of the progressive changes implemented by the Clement Attlee government — but that government was not operating in a void. The strength and demands of the mass labour movement were a constant influence on it. Similar pressure will need to be applied to the parliamentary party under Corbyn. We on the left have a mountain to climb, even if Jeremy wins — but this movement is anything but defeatist. Whatever the Blairites say, peace and socialism can win.