David Cameron has delivered a fresh warning that councils must draw up plans to build thousands of new homes - or the Government will do it for them.
The Prime Minister highlighted a 2017 deadline for authorities to put together blueprints for helping to deliver a million homes over the next five years.
A fifth of councils have yet to publish plans - which set a trajectory for constructing homes in the area over a 15 year period - and 65% have not fully adopted one.
"A Greater Britain must mean more families having the security and stability of owning a home of their own," Mr Cameron said. "My Government will do everything it can to help people buy a place of their own - at the heart of this is our ambition to build one million new homes by 2020.
"Many areas are doing this already – and this is great – but we need a national crusade to get homes built and everyone must play their part.
"Councils have a key role to play in this by drawing up their own local plans for new homes by 2017. But if they fail to act, we'll work with local people to produce a plan for them."
The warning came ahead of the publication of the Housing Bill, which will require the inclusion of affordable starter homes when development sites are big enough, and make planning permission in principle automatic on brownfield sites.
A temporary rule introduced in May 2013 allowing people to convert disused offices into homes without applying for planning permission is being made permanent – after almost 4,000 conversions were given the go ahead.
The government is also launching the www.ownyourhome.gov.uk website to help people find the right homebuying scheme for them.