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
IS is now attracting women and whole families as well as young men - but will any return to carry out another 7/7?
Rain will be heavy across Scotland, parts of northern England and Wales tonight - rumbles of thunder are possible waking some of us up.
A report out tomorrow shows energy bills have been 5% higher than they should have been - costing Brits as much as £1.2 billion a year.