Almost 600,000 Labour members will get their leadership voting papers starting today. Too little about the party’s leadership election to date has suggested a way out of the existential crisis the party and social democracy more widely are in. So, as members ponder their vote, what might a road to real renewal look like?

Let’s start where we are. If it wasn’t so serious it would be laughably shambolic to interview and select a new leader of an organisation before that organisation has decided why it keeps failing and what its purpose is at the start of the third decade of the 21st century.

But that is what Labour is doing. Going through the motions, yet again, of loading impossible expectations on a single person with little if any regard for the bewildering context and complexity of the challenges facing progressive politics. It’s just hit and hope. A new messiah that will do it all for us and to us, until of course they are found out and the process is repeated, a little to the left or the right of the previous incumbent.

But let’s for a moment imagine a world in which we have stepped back and thought hard about the who, what and why of Labour and what the key tasks of any new leader is before we appoint them. This is my take; you will have yours.

The first requirement of leadership is strategy, not just a strategy for office, the occupation of the state, but a strategy for power, defined as the ability to transform the country. Taking and holding office is necessary, but insufficient. Power is about the forces, ideas, people, organisations and alliances that can enact big and reasonably permanent change. What is the progressive agent of the 21st century – the political sociology that will drive the transformation we desire? Without such countervailing forces Labour is nothing.

Such a strategy demands an understanding of context. Where are we as nation? What is the cultural and technological moment, and what are the big forces and issues that hinder and help us? Never have the answers been more complex. And then where do we want to get to? What is the vision of the good life and the good society we want to enact? Strategy has to link the two in a way that bends modernity to socialist and progressive values. This is really hard but essential. Without a strategy a party of the left is just blowing about in the winds of change.

Then comes a series of building blocks to get us there. A plan. Not a blueprint but steps that strike a popular chord by being both desirable and feasible. A new common sense built around frames, arguments and symbolic polices that assemble an electoral and social coalition for change.

In all this, any leader faces the paradox of power and principle. Too much of either pens us into a dead end. Some leaders concede too much, others too little. The answer isn’t to triangulate to some imagined ‘soft left’ sweet spot but to negotiate the dichotomy by building forces and arguments that change the terrain on which we operate. So, for instance, you don’t decide Labour is all for towns or all for cities, but what language and positioning transcends such polarisation. The truth being that, despite those who sow division, we are all from somewhere and nowhere.

But the biggest challenge to any new leader is cultural and quite personal, in that it’s not all about them and it’s not all about now. The job is too big and complex to think it can be navigated by one heroic figure. Knowing and demonstrating that power is now distributed is critical to 21st century leadership. And of course, to get the job candidates have to say only they can win next time. But along the way a good leader puts in place building blocks their successor can work from. Otherwise the party starts from scratch every time.

So, can the new leader demonstrate they get the collaborative nature of the 21st century? That in the face of incredibly complex demands, nationally and internationally, with fragmenting allegiances and fluid identities, they get that the future will be negotiated not imposed? The temptation is to get up earlier and go to bed later than your enemy, as both Lenin and Thatcher did. This must be resisted. Instead, they should read, think, listen and trust as much as possible. Today leaders must look like they’re having fun – hopefully because they are. They should be humble and bold, because we trust and listen to people who are strong enough to express their vulnerability - the cradle of creativity. To help them understand all this, two wise leaders, Sue Goss and Ruth Lister have written a handy job and person spec for such 21st century leadership here.

At heart, this new cultural approach is plural, the belief that better and more enduring answers are found from diversity not uniformity. This applies as much inside the party as outside. Labour may be the biggest opposition force, not least because the electoral system forces millions to tick its box, but it can longer be the sole agent of transformation. The task is too big and complex.

Rather than rely on the diminishing power of coercive first past the post democracy, a powerful new leader knows that a more radical, shared and devolved democracy is the strongest weapon progressives have to change things in big ways.

In all this, the task is to understand how organisations really work in the 21st century as participatory and collaborative entities, and push that approach in both the public and private sectors. In short, they must develop a new operating system of governance for our times. This future is already being created in the gaps between the remote state and free market. As changing needs combine with new capacity, and is accelerated by platforms and networks, our interconnectedness is being deepened. The next leader should ask the likes of Alex Fox, CEO of Shared Lives and Hilary Cottam author of Radical Help to advise on how to surf this emerging and rich participatory terrain.

Being good at ‘Opposing’ the government, harrying and chasing them are necessary skills, as is general competence. But they are not sufficient. A successful new leader must challenge Labour to change. Not when it gets into office but now. Because they have power now to act and prefigure their time as prime minister. Working with councils, community groups, citizens, companies and other progressive parties and organisations they can show how they will lead and not just tell. They should use the Party not merely as an electoral machine but as the laboratory and shop window to the country to demonstrate their culture, values and priorities.

To succeed Labour’s next leader has to tell a very different story about the party’s past, present and future so that we don’t waste the next five years.