Labour risks irrelevance unless we act. Britain is soul searching – trying to work out our new identity in the world, how to heal division, and what kind of country we want to be. A strong, Labour voice is essential, to take on the new prime minister as well as build broad support across the country.

Most immediately, Labour’s failure to be that loud, strong voice is down to our leadership; change is urgently needed, and that’s why I’m strongly backing Owen Smith’s campaign. The challenge for our party is broader than the leadership election. We may argue amongst ourselves about whether we are too far to the right or left, but the real question is whether our whole movement is being left behind.

This Labour battle isn’t Blairites v Corbynistas. It’s over progressive change | David Wearing Read more

We were founded as the party of labour, the party of work, in the furnaces, factories and coalmines of the industrial revolution. The Fabians and trade unions joined together to pursue the parliamentary route to socialism – with a strong vision of the action needed to end exploitation, challenge inequality and deliver security in an industrial age. As work changed in the white-collar revolution, Labour policies adapted to keep up. We championed technology, new universities, the unionisation of public-sector workers, new rights for women, an end to discrimination, the national minimum wage, tax credits and Sure Start.

Today globalisation, accelerating technological development and demographic change mean work is changing faster than ever. But while the Tories don’t have the answers, this time Labour isn’t keeping up either. For some people, great opportunities in science and creative industries are emerging. But many others face new insecurity and desperate exploitation. The labour market is hollowing out as middle-class and low-skilled jobs are replaced by new technology. Inequality is growing.

Low-skilled agency and self-employed workers are caught in a race to the bottom. The Sports Direct owner, Mike Ashley, is worth nearly £5bn – yet his business’s success has been built on zero-hour contracts and clever ways to circumvent the minimum wage. According to the Bank of England and the IMF, the scale of inequality is hampering economic growth.

There is a growing geographic divide, too – and not just between north and south. Big cities have become more diverse, vibrant, creative places, with new jobs and new ways of working springing up. But industrial towns have lost their sense of identity and purpose as old manufacturing workplaces have declined. The places and people who see globalisation as an opportunity voted to remain in the EU, while the towns and lower-paid workers who face many of the problems voted to leave.

Rightwing parties will never be able to solve these challenges. Free marketeers shrug their shoulders about widening inequality or exploitation – it’s a matter for market forces. Six years of Tory government has just widened inequality: there’s been no proper plan for the science investment and digital skills we need, while social security, protection and solidarity are being undermined.

That’s why Owen Smith is right to be campaigning on inequality, insecurity at work and jobs - including embedding the fight against inequality in Labour’s clause IV, new policy ideas and infrastructure investment, not cutting investment in innovation and research as Jeremy Corbyn and John McDonnell seem to want to do.

Because Labour needs to keep up. We are losing our traditional support as the working class fragments and people’s sense of identity changes. Trade unions aren’t reaching those in insecure work, including those who need workplace representation and protection most. The Labour party is neither inspiring those who want to get on, nor empowering those who feel angry at the lack of control they have over their lives. I fear we are in danger, under Corbyn’s leadership, of becoming predominantly a party of the big city, too detached from the industrial heartlands and coalfields where we were first founded and which badly need a Labour government now.

Our historic passion for equality, opportunity and social solidarity, and our historic fight against injustice are more important than ever. Work has always given us in the Labour party a sense of common purpose, identity and a vision of the future. We must reorganise ourselves around a strong vision of work in the digital age, where everyone can benefit from technology and globalisation.

From radical new policies for a digital skills revolution to a new employment agenda for towns, from reshaping trade unions to reach fragmented workplaces to a new social contract to give families security, from investment in science and childcare to new laws against exploitation: these are the kinds of ideas being explored by the Changing Work Centre, which I chair, set up by the Fabian Society and Community trade union.

Labour has to offer hope to those who want new opportunities and security for people threatened by change. Our task is to develop new ways of building common purpose, social solidarity and community around work in a digital age.

• Yvette Cooper is chair of the Changing Work Centre and editor of its first book, Changing Work: Progressive Ideas for the Modern World of Work, published this week.

Trade unions aren’t reaching those in insecure work, including those who need workplace protection most

• Minor amendments to this article resulted when the final draft was substituted on 27 July 2016 for an earlier draft, which had been supplied in error to the Guardian and briefly published.