The Government must be "honest and upfront" about plans to build new garden cities in south east England, Nick Clegg has said.
The Deputy Prime Minister acknowledged that the green belt was being "eaten away" by urban sprawl and there was a need for the new planned cities rather than relying on further "piecemeal" developments.
He insisted that a plan for the new cities would be published and Mr Clegg said there was "no point in hiding" from the fact that they were needed in the south east.
The Daily Telegraph reported that a draft proposal suggests two new settlements in Yalding, Kent and Gerrards Cross, Buckinghamshire.
In an article for the newspaper Mr Clegg wrote: " We cannot make the mistakes of past governments and sit on our hands while a whole generation of people are squeezed out of the housing market. It is our duty to change the story.
"We must bring decades of indecision and stagnant political will to an end.
"That is why I am a strong advocate of garden cities, where there is clear local support and private sector appetite. In 2011, our housing strategy committed us to publishing a prospectus for new garden cities and that is exactly what we'll do."
The current situation had led to "bloated" town and cities " being forced to expand further bit by bit, and the green belt is being eaten away".
But Mr Clegg claimed garden cities could protect the countryside, and it would be possible to build them without concreting over the green belt, National Parks or Areas of Outstanding Natural Beauty.
Although he stopped short of identifying specific sites earmarked for development he said: " We must also be honest and upfront about where they will be. There's no point in hiding from this: there is an arc around the south east of England where demand is past breaking point.
"The current situation is bad for the economy and places a massive strain on vital services. Where there is more work and more demand, we should bite the bullet and create garden towns and garden cities."
The Liberal Democrats have previously claimed the Conservatives are suppressing the report and party president Tim Farron accused the Tories of a "Nimby attitude towards garden cities" which are likely to be in their political heartlands.
Lib Dem leader Mr Clegg wrote: "I believe that if we put aside partisan politics and think collectively about the housing needs of the next generation, we could set Britain on track for a major wave of new development, new jobs and new hope."