Jon Cruddas has been the MP for Dagenham since 2001, and for the Dagenham and Rainham constituency since 2010. During the course of a 35-year career in the Labour party, he has become one of its most respected intellectual figures, standing for the deputy leadership in 2006 and chairing the party’s policy review under Ed Miliband. His new book, A Century of Labour, is a sweeping historical survey of the party’s ideas and personalities since its formation. Cruddas lives in London with his wife, Anna. He will be standing down as an MP at the next election.

Your new book is about Labour’s history, but also speaks directly to the present moment. Your criticisms in it of Sir Keir Starmer’s “elusiveness” as a leader made the front page of the Observer. How worried are you about Labour’s direction of travel under his leadership?
Keir Starmer deserves great credit. He inherited a party 20 points behind which is now 15 ahead. He could become only the fourth Labour leader to win a general election. I do worry for him, though. Having entered politics late he remains curiously rootless in terms of Labour’s history, its factions, and intellectual traditions. This has an upside. He is not trapped by history and is agile.

Yet this elusive quality could become captive to Labour’s utilitarian politics. I fear this has already happened as he has conceded far too much to Labour’s hard right wing. In the short term this might appear tactically smart, yet being beholden to such factional politics will cut Starmer off from vital sources of political and intellectual energy once in power. He needs to establish a deeper public philosophy and rebuild a political coalition to sustain him in office. The success of the next Labour government will depend on it.

As it goes into the election campaign, is the party striking the right balance between pragmatism and idealism?
It’s a work in progress. Every successful Labour government has been preceded by waves of revisionist thinking – to reimagine social democracy, navigate the modern world and instil the grip, energy and intellectual vitality necessary to change the country. This creative work underpinned the successes of the Attlee, Wilson and Blair administrations. Yet since New Labour left office there has been no such revisionist project and globally social democracy is in retreat. Starmer’s five missions are a start, especially around industrial policy and labour rights, but more needs to be done.

Throughout your career you have tried to highlight the value of an ethical socialist tradition that emphasises ideas of “virtue” and “the good life”. Do you think the left has lost touch with this way of thinking?
In the postwar era, Labour sought to civilise capitalism and regulate the market through the formation of the welfare state. It was Attlee’s New Deal for the British people. Yet today progressive politics appears underpowered. Why? Partly because our thinking and vision have shrunk and become overconcerned with allocating resources – questions of material justice – and we have handed over ethical questions to the market. Consequently, we have become far too blinkered in terms of an appreciation of the lives people wish to live.

Does this help account for the emergence of the populist right, for instance Reform UK?
Yes. For the moment, the long-term corrosion of the centre left is being disguised by a disintegrating Tory government. This won’t last long. The advance of authoritarian populism means that to safeguard liberal democracy, Labour has to rediscover its moral purpose. This extends beyond simply our capitulation to the market, however. I would argue the forces feeding the populist right – questions of worth and esteem, resentment, pain and humiliation – are moral challenges. Yet we recoil from this territory because of our insistence on liberal neutrality on moral issues and we therefore become detached from the everyday concerns of people, safe in our language of rights, opportunity and fairness.

After almost half a century in politics you will step down as MP for Dagenham and Rainham at the next election. What’s the plan?
My wife, Anna, and I will disappear to the west of Ireland for a lot of the year. There will be plenty of surfing, fishing, golfing and climbing. I am also kicking around studying oceanography in Galway. And I have a few book projects. One is a 20th-century history of the working class told through the Dagenham story. Another around a modern New Deal politics. A third on the neglected role of Irish migration in Labour history.

What was the first book you fell in love with as a child?
As a kid I was not bookish at all, preferring sport! But when I started to read, Seamus Heaney’s poetry had an enormous influence on me, especially his reflections on the Troubles in the north. Like Yeats, a public poet both profound and accessible.

What are you reading now?
I am rereading Emmet O’Connor’s biography of Big Jim Larkin, an extraordinary socialist and trade unionist whose life should inform today’s desire to rebuild the power of the working class. Also Eric Rauchway’s Why the New Deal Matters. I have become somewhat obsessed with the idea of a modern New Deal. As a family we were extraordinarily socially mobile. I had the right to free education and health, access to housing and decent work. Much of that is gone. So can we provide new economic and social rights for all our citizens, especially our young? Though the book I will read this Easter is The Letters of Seamus Heaney.

Which other recent books about politics have you admired?
To rebuild the country and reject austerity we have to tackle obscene wealth. Ingrid Robeyn’s Limitarianism is a brilliant intervention to do just that. Mike Kenny’s Fractured Union is a timely guide to British disunity.

Are you a novel reader at all? Which was the last one you really enjoyed?
I read novels recommended by Anna. Plenty of John Banville and Anne Enright. Solar Bones by Mike McCormack was a highlight. Paul Lynch’s Prophet Song disturbed me, but was of the moment. Occasionally I strike out on my own – A Spy Alone by Charles Beaumont was fun.

• A Century of Labour is published by Polity (£25). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply