Who’d a thought it but how GLAD I am… I would not be anywhere but in England this day… secretary at work was delighted, says he had lived all his life for this day. Nice to have a prime minister whose wife does some housework and her own shopping.’

Edie Rutherford, Sheffield housewife and diarist for Mass Observation, perfectly captures in her 27 July 1945 entry the mix of golden moment and pragmatic reflection that was the secret of Labour’s general election landslide at the end of the second world war.

Despite her surprise at Labour’s victory and its size – one shared by many other Britons that summer – context is all in providing the explanation and in making useful comparisons with that second ‘golden moment’ landslide – of 1 May 1997. The crushing defeat of the Conservatives in 1945 was not just based on memories of the 1930s but on the growing national wartime consensus that collectivism, fair shares and a more egalitarian society would work for Britain after the war as well as during it. The reception of Beveridge’s blueprint for a national health service, the 1944 Education Act – all these set the wind for a Labour victory when the war was ended, together with the new climate of classless discussion in the armed forces, Brains Trusts on the radio, Left Book Club and Fabian pamphlets, and common suffering and rationing on the Home Front.

The ability of the Attlee government to carry through major changes in Britain’s postwar social and economic landscape was formed as much by those wartime experiences as by the immediate postwar period – and they favoured a left-of-centre ideology and faith in planning in British society that was unprecedented. Edward Heath and Denis Healey, Balliol College contemporaries and student opponents of prewar appeasement, may have emerged from their wartime armed service on different political sides, but both epitomised the ‘one nation’ bonding across the classes that experience produced.

Where are the lessons or parallels of this for 21st-century Labour entering its third term – one the Attlee government never had? In 1997, as in 1945, there was a golden moment – New Labour, New Britain, the idea of a young country and a young Tony Blair – but this time it was more zeitgeist than ideology. So terrified was New Labour (rightly) of its 1980s ideological turmoil that the promises were tightly drawn and far from revolutionary.

Being ideology-lite – at least in comparison to the postwar Labour government – has been a great strength in the eight years since then in enabling Tony Blair in a very different historical context to embody the sort of one-nation consensus that brought Labour such a fair wind in 1945. But while we have not had the great ideological divides in the party of the early 1950s or early 1980s, neither have we been able to sustain the mass party that carried the Attlee government’s message through. ‘Events, dear boy, events’ – Afghanistan, 9/11, Iraq – whatever view people take of the government in those contexts, they have soaked up great swathes of energy and opened up new divisions.

Despite that, the government in its third term can look back on very solid economic, social and constitutional achievements – arguably as solid as and more far-reaching than the legacy of 1945 to 1951. But just as planning was not enough for Attlee and his colleagues, nor will economic competence by itself be enough to sustain New Labour. In the worried, frenetic, atomised world we now inhabit, the need for big ideas and the sort of idealism that prompted the delight of Edie Rutherford and thousands like her 60 years ago has grown, not diminished. And that is why the challenge is to forge a new direction out of the big questions – social connection, climate and environmental change, globalisation, confronting fundamentalism and fanaticism in all its forms – with big ideas that go beyond focus-group feedback.

To do those things, Labour has to re-embed and then maintain the sense of common purpose that sustained the British people through long years of war and made the heart of the party’s 1945 election message – ‘we’ve won the war, now let’s win the peace’ – seem not just a natural continuation but an uplifting programme for the future. But of course the worlds of 2005 and 1945 are enormously different. If ‘socialism in one country’ was much of an illusion in 1945 so any ‘-ism’ in any one country is impossible today. But that does not mean that our government cannot give big leads to global big issues – as the debt and Africa campaigns are trying to demonstrate.

Common purpose was perhaps inevitably an easier objective in the largely monocultural and substantially monoethnic (though still deeply class-ridden) Britain of 1945. Shared values are often harder to construct (though not necessarily to maintain) in multi-choice societies of consumer plenty than in those of relative scarcity – like postwar Britain. But the attempts to do so must go right to the top of the list – given added urgency by this July’s events in London and the debate about the balance between security and the obligations of British citizenship and civil liberties in our multicultural society now being endangered.

The wartime song cheered its listener with the promise that ‘there’ll always be an England… if England means as much to you as England means to me.’ But there’s the rub – in 2005 what sort of England-Britain (the necessary change from the wartime song tells us all) do we want to mean the same to us? The heartening solidarity in London in the wake of the bombings – across all ages, faiths and ethnic groups – make it clear that the meaning is not as hard to define as the bigots and extremists would like to suggest. But let us not delude ourselves – we have to work at it.

In practical terms, it means both tapping into the resources and defusing the frustrations of both younger and older people – the latter’s perspective rising rapidly up the agenda as their demographics do. It means renewing voluntarism and strengthening through education at all levels and all ages the knowledge of our past, our institutions and what British citizenship really means. And it means renewing local and regional pride and sense of identity – building on the city renaissances of the north and the Midlands over the past 10 years.

And it needs to be said – baldly – that for all the private sector involvement and leads offered by the voluntary sector, it’s primarily the British state – linked to its European and global partners – that has to start setting the frameworks and agendas for this.

This is not to argue for a lost utopia or a new Jerusalem. As Bryan Appleyard wrote recently, ‘whatever the British are at any given moment, they were invariably something different a moment before.’ But I think that’s something our Labour-supporting diarist, Edie Rutherford – a white South African immigrant living in postwar Sheffield – would have understood. Common purpose demands more than just economic prosperity and means moving beyond aimless consumerism and celebrity voyeurism. We have made an important start but we’ve a long way to go – and perhaps not that much time to do it in.