Ed Miliband has accepted David Cameron's cuts. Ken Livingstone shares Boris Johnson's commitment to business. And according to one-time wannabe Scottish leader Tom Harris, Labour "want you to get rich". Today's party owes little to Methodism, let alone Marx. But if Labour has lost its soul, the Tories never had one and the Lib Dems sold theirs a long time ago.

All three embrace a materialistic commitment to modern capitalism – they just differ in how it might be made a little nicer. It is the Green party that now embodies the natural political expression of the more progressive traditions found in dissenting movements such as Quakerism and radical Catholicism.

Many are asking what the point of Labour is, particularly as the time is ripe for an economic vision that refuses to bow at the altar of growth – one that sees people as fully human, not competitive economic units. The charge of "naivety" that once held back such a perspective rings rather hollow today. It is the free-market narrative that is now discredited. Relentless and largely illusory growth based on credit was unsustainable. Inflation driven by rising commodity prices following the depletion of scarce resources has made a monkey out of monetarism. And this in addition to the huge human, social and environmental cost, seen in rising inequality and pollution. "Responsible capitalism" is an oxymoron akin to "well-mannered war".

An appeal to give up the pursuit of wealth isn't an automatic vote-winner. But the alternative to the pursuit of riches is pursuit of a richer vision: neither austerity nor excessive wealth, but rather "sufficiency plus", where needs are met, and then some, while a fuller understating of human welfare is championed.

Having less can be more. Too much choice is not liberating. There is something to be said for rhythms of life, for patience and delayed gratification, where everything isn't available instantaneously. Seasons are enjoyed because they aren't there all year round. Fifty-hour weeks come at the expense of family and friends. That's if we have a job at all.

As well as robbing us of our lives, the system pits us against one another in an endless quest for more, which fuels greater inequality, dissatisfaction and unfulfilment – for both the winners and the losers. We feel left behind our neighbours and other countries if we don't better ourselves economically. We have forgotten who the economy is for.

The alternative is not state socialism. There has always been trade, exchange and barter. But modern capitalism is a relatively late arrival. There are alternative economic models, from mutuals, industrial provident societies and credit unions to small businesses and trading ventures that operate with counter-cultural values. Right now there are more members of co-operatives in the UK (which, the Co-op group points out, have outperformed the British economy by over 21% since the start of the credit crunch) than there are shareholders.

The great leaders of the next few years will not be those who career down another blind alley on the coat tails of outdated and damaging economic models. They will be those who can manage a transition economy, through inevitable de-growth, on to a more sustainable footing. They will need to foster a "wartime spirit", perhaps, but where the common enemy is not the financial crisis. If we see it in those terms, the competitive nature of the system means we can never truly be all in this together. All we do is sacrifice the most vulnerable for the sake of the system. The real foe is capitalism. One way or another we'll wake up to the fact.