On September 24, Jeremy Corbyn is expected to be re-elected leader of the Labour Party, which means he will have won two leadership contests in just over a year. While not unassailable, he will feel vindicated for resisting the demand from most of his MPs to resign.

That his most senior detractors in the party have fallen silent will further embolden him. The former Labour leaders who earlier in the summer denounced Corbyn now have nothing to say. There have been no major interventions in recent weeks from Tony Blair, Neil Kinnock, Gordon Brown or Ed Miliband. No fiery speeches made or compelling articles written outlining the depths of the Labour crisis and what needs to be done.

In private they denounce Corbyn – they speak of the ‘tragedy’ of it all – but publicly they are quiet. They show no fight, merely a kind of meek acceptance of the inevitable. It’s almost as if they are in denial – or have given up.

What’s going on? Why isn’t there more fight? ‘It’s because there’s a general feeling of hopelessness,’ Labour grandee Roy Hattersley told me. ‘This is far worse than the early 1980s. I had hope then. Now I don’t have any.’

There’s a saying by the Italian philosopher Antonio Gramsci that is a favourite of the Left: ‘Pessimism of the intellect, optimism of the will.’ It refers to the long struggles on the Left to challenge and rectify concentrations of wealth and power as well as to disrupt established hierarchies.

The history of the Labour Party has been characterised by struggle and fight, the fight to enfranchise the populace and build the institutions – the NHS, the welfare state, the good state schools – that could transform working people’s lives for the better and create equal opportunities for all.

Nowadays, apart from the Corbynites, there’s no optimism of the will among most of the party’s MPs. Instead, there is only pessimism of the intellect (they have no idea how to renew and become a unified election-winning force again) and pessimism of the will (even the desire to fight is draining away).And the EU referendum, in which a third of Labour supporters voted for Brexit, has demoralised them further. The forces of globalisation, immigration, stagnant wages, rampant inequality, precarious rather than stable jobs, digital disruption – all have contributed to the crisis on the Left in the UK and the rest of Europe, where moderate social democracy is in retreat.

Labour’s traditional voters – those who voted for Brexit – feel let down and left behind. They feel alienated from metropolitan liberals and the London Left, and are turning to Ukip, the SNP and Theresa May’s Tories.

Labour MPs know what is wrong because their constituents tell them so. As a consequence, their mood is as bleak as I’ve known it. The party’s support has collapsed in Scotland, and most of the 106 gains that Labour will need to win a majority after the constituency boundary changes are in England, where the party is weak.

The rebellion against Corbyn that, in the aftermath of the Brexit vote, began with mass resignations from the Shadow Cabinet and an overwhelming vote of no confidence by MPs in the leader, is ending in a mood of sullen resignation in the Parliamentary Labour Party (PLP). Corbyn’s supporters are, by contrast, jubilant, and they should be.

The challenge to Corbyn this summer has been feeble. The onus was on the PLP to come up with something different, ideas and a broad analysis of what has gone wrong and what should be done. This has not come close to happening.

The leadership contest has been an ideas-free zone and a procession for Corbyn, who has toured the country doing what he does best – bolstering the true believers at events that often have the feel of religious revivalist rallies.

The challenger to Corbyn, the Welsh MP Owen Smith who is from the ‘soft Left’, has offered little beyond self-belief and a certain dogged persistence. He has shown more courage than many of his colleagues in taking on the challenge when others cowered or equivocated, but he has made too many gaffes.

Smith’s policy proposals are largely the same as Corbyn’s. He delivers the same statist, anti-austerity rhetoric. His message amounts to no more than this: ‘Like Jeremy, I am of the Left and for the Left, but I’m more competent than he is.’ Be enthused by that, if you will.

That Smith emerged as the sole challenger proves Corbyn is winning more than the leadership contest. He and his shrewd Shadow Chancellor, John McDonnell, who is now the real power in the remade party, have successfully dragged Labour to the radical Left. With the backing of the Unite union, they are now determined to complete the job by taking control of the crucial policy-making National Executive Committee and begin selecting more MPs in their own image – which obviously means deselecting others.

But this isn’t a Trotskyite takeover. Corbyn has been democratically empowered by the membership. No one was coerced into voting for him. Clearly, Labour members want him and his socialist populism, even if, judging from the polls, the electorate resoundingly does not.

The brightest talents on the Labour benches – Yvette Cooper, Chuka Umunna, Dan Jarvis, Keir Starmer – are becalmed. Perhaps they simply don’t know how to respond or fight in the way Denis Healey and Roy Hattersley did to save their party during the Bennite wars of the early 1980s. Perhaps it was all too easy for them on the way up, when the Left was marginal and Blair was winning landslide majorities. Perhaps they are constrained by members and activists.

Several moderate MPs I know have spoken of giving up on politics altogether. Others, such as Andy Burnham, a leadership frontrunner only last summer, want to pursue careers away from Westminster – he’s the favourite to become the next mayor of Manchester.

So here’s the essential question for Labour, the answer to which will define its prospects over the next decade and beyond: is it content to be a mass membership movement of anti-capitalist radicals, or does it aspire to be a party of government capable of appealing to moderate voters who do not live in cities?

In Theresa May, Labour is up against a Prime Minister much more formidable than David Cameron, the gilded Old Etonian Notting Hill liberal. Her meritocratic Cabinet has more state- educated Ministers than any previous Conservative government, and more than all Labour governments since Clement Attlee’s in 1945. With Ruth Davidson now the most popular politician in Scotland, the Tories are beginning to look and sound like the rest of the country.

Mrs May has made a direct appeal, too, to those voters who are ‘working hard, but just managing’. That message resonates.She does not want to govern for the few, but the many.

If she can deliver on these promises, her reform conservatism could condemn Labour to electoral oblivion. Is this what the heirs of Labour’s greatest prime minister, Clement Attlee, want for their party?