Nick Clegg is calling for the creation of a new generation of new towns and garden cities to address Britain's growing housing crisis.
The Deputy Prime Minister warns that unless radical action is taken to boost housebuilding, for many young people their dreams of a home of their own will be no more than a "pipe dream".
In a speech to the National House-Building Council, he will say the Government is making available £225 million in funding to "unblock" a series of major local housing projects which have "hit a wall".
Together, the schemes - which range in size from 4,000 units to 9,500 - will provide up to 48,600 new homes.
However, Mr Clegg will say the shortage of homes is becoming so acute, there will in future need to be even more ambitious, with new developments of 15,000 to 25,000 homes.
He will say they should draw inspiration from the garden cities of early 20th century, such as Letchworth and Welwyn, and the new towns of the post-war era like Milton Keynes and Stevenage.
"It's time to rediscover that proud tradition of creating new places," he is expected to say.
"We can either condemn ourselves to haphazard urban sprawl - the surest way to damage the countryside, we can cram ever more people into existing settlements, concreting over gardens and parks - and bear in mind we already build the smallest homes in Western Europe, or we can build places people want to live.
"Places which draw on the best of British architecture and design, which have their own identity and character, which - rather than destroy the countryside, actually have a crucial role in keeping it intact."
He will say that the shortage of homes for young people has created a "generational shift" in the debate, with people becoming more receptive to the idea of new developments which in the past would have been strongly resisted.