Nick Clegg will say the new cities 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.
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.
More top news
The garden of paedophile friends of serial killers Fred and Rosemary West is being dug up by police after a tip-off.
A man has been arrested on suspicion of murder after a woman's body was found in south Wales.
After the Indiana polls close, ITV News asked Ted Cruz supporters if they could back Donald Trump as the Republican presidential nominee.