It used to be said that oppositions never win elections, governments lose them. Maybe that once held true. But not here – and not this time. This Wednesday marks exactly one year before the date of that general election. We are clear that on 7 May 2015 Labour will have to win the argument and so give Britain the change election we never had four years ago.

The last election was held in the immediate aftermath of the global financial meltdown. The next must be a chance for voters to decide the direction of our country, how it is run – and who it is run for.

We are confident that the Conservatives are beatable. It is 22 years since they last won a parliamentary majority. Their membership – with an average age of 68 – is poised to fall below 100,000 for the first time. And any lingering sense of compassionate Conservatism has evaporated in the toxic fumes of a party being dragged to the right by its own backbenchers and Ukip.

But they can still be expected to outspend us by as much as three to one, while David Cameron is promising to dust down the playbook of smear and fear from 1992, knowing that large sections of the press can be relied upon to help him.

The outline of how they will fight could be seen last week when Ed Miliband launched our local and European campaign with a sensible market-based policy on rents. The Tories responded by comparing him to Hugo Chávez.

No matter how wrong-headed and out-of-touch this government becomes, we cannot expect the pendulum to swing back automatically. Already much work has been done to re-establish enduring components for Labour's electoral success: clarity of strategy, effective rebuttal, and superior field organisation with our network of community organisers.

Much else is changing fast. Politics is increasingly on the periphery of an ever-multiplying range of media competing for people's attention while also subject to higher levels of cynicism than ever before.

So to win a clear majority in 2015, Labour's strategy for the year ahead is organised around three imperatives.

First, in this post-crash election, Labour will lay before the British people the boldest, most radical offer in a generation. One of the reasons David Axelrod has agreed to join our campaign, having masterminded Barack Obama's presidential victories, is because Ed Miliband is a leader who understands the scale of the challenge in reconnecting the wealth of economies like Britain and America to the everyday family finances of their people.

Under his leadership, Labour has placed the cost-of-living crisis on the centre stage of British politics. It is a crisis that demands we reform the market, while the fiscal problems we will inherit mean we must be reformers of the state too. That is why Jon Cruddas's policy review is delivering bold ideas such as devolving power away from Whitehall, integrating health and social care, and setting out new approaches to making work pay.

Second, we will show we have moved on from the past. Instead of trying to convince voters they were wrong to reject us in 2010, Ed Miliband has learnt from the British people's desire for change. He understands that a party committed to social justice must respond to real concerns that immigration has, in some communities, led to undercutting of wages and conditions.

And he recognises it is not enough to be different and radical – we must be credible too. Our plans for government will be based on the firm commitment that Labour will balance the books and secure maximum value from every penny of taxpayers' money.

Finally, we have a responsibility to set out clearly the consequences of a second term of Tory government for decent jobs, our NHS and the living standards of hardworking families – while pinning the Liberal Democrats to their record of propping up David Cameron.

This is the strategy on which Labour intends to secure a majority in a year's time. We aspire not only to run the country but to change the way the country is run, so we will have to overcome powerful interests determined to stop us.

Bringing change is never easy. But this is how Labour will win.

Douglas Alexander is chairperson of Labour's general election strategy. Spencer Livermore is general election campaign director.