We must raise our ambition and build many more homes

With a new prime minister, Labour needs to seize the opportunity on housing - including new eco town

From "concreting the countryside" to eco towns: we have come a long way in the housing debate in the past two years. When John Prescott set out his housing plans a few years ago, the government was attacked for proposing too many homes. Now, Gordon Brown's new towns have been welcomed and the government is challenged for delivering too few.

Housing is increasing at its highest rate for nearly 20 years as a result. But we have not yet been ambitious enough. Current targets need to be higher. With a new prime minister, this is the moment to raise our sights. It is also the moment to challenge the Tories on housing - if they want to get serious about the aspirations of the next generation, they need to start backing at local and regional level the new homes Britain needs.

If we don't do more, housing will become the greatest cause of widening inequality over the next ten years. We have an ageing, growing population with more people living alone and the truth is this country hasn't been building enough homes to meet rising demand for decades. House prices have doubled in the past six years and more than quadrupled in the past 20 years, as a result. Talk to young couples from Midhurst to Manchester and you hear how many of them already depend on the Bank of Mum and Dad to get them started. And that's deeply unfair on those who can't get family support.

We need more social housing and shared-ownership homes, too. New social housing is up by 50 per cent in the past three years, but we need to go much further. Over recent years the investment priority has been refurbishing existing council homes. Nevertheless, the urgent need now is for more social housing, with councils and housing associations both able to build more.

The stark evidence of rising house prices is changing attitudes. Several years of concerted campaigning to change public views are making a difference too, as government-backed reports on the link between rising prices and lack of supply are starting to sink in. Websites such as ww.pricedout.org.uk are marshalling the voices of frustrated young first-time buyers. Deputy leadership candidates (all six of them) are calling for more affordable homes.

Zero-carbon homes have captured the imagination, too. The programme to improve design and cut carbon emissions from new housing is one of the most ambitious in the world and is helping to change the politics of housing. Now the Campaign for the Protection of Rural England, alongside WWF and Friends of the Earth, all say we need more homes, so long as they are built in a sustainable way.

But this means Labour now needs to seize the opportunity on housing - including new eco towns and bolder plans. Current targets to build 200,000 homes a year by 2016 will not be sufficient to keep up with rising demand. New homes are needed in the north as well as the south. The gap right now between the number of new households being formed and the number of homes built is actually bigger in Yorkshire than it is in the south-east. Further reforms are needed on top of recent planning changes and investment in infrastructure to make sure the homes come through.

Of course the real challenge is still to win the argument for more and better quality homes in every town and community, where local councils play such an important role in delivering (or blocking) development. It is easy to back new homes in principle, while somehow objecting to all the locations in which they could ever be built.

Too often Conservative councils are still arguing strongly against more homes. The Tory-led South East England Regional Assembly has adopted the utterly bonkers position that new house building should be cut rather than increased. So far David Cameron can just about get away with warm words on housing nationally, while his troops block them locally. But with the growing spotlight on housing, such contradictions will not hold. Housing will be the next grammar schools: when it comes to real policy, the Tory reactionaries win through.

Harold Macmillan's Tories would have been horrified at the hostility of Cameron's party towards more homes. In the Sixties, every party campaigned for 300,000 new homes a year. This shows it was possible to build consensus around major housing change. Previous generations managed it because they recognised the shocking consequences of denying families affordable quality homes of their own.

Brown has made clear his determination that the Labour government should make housing the priority now, in order to help future generations. The challenge for Cameron is whether he has the values or the strength to take on his party and join the consensus for more homes.

Yvette Cooper is minister for housing and planning