Just one in five homes for sale in England are affordable for the average working family, according to housing charity Shelter.
It says more than 80% of properties for sale are unaffordable, with fewer than 10 affordable homes for sale in each of 83 areas (a quarter of England) across the country.
The survey indicates that, rather than being centred in London and the south east, the "affordable homes crisis" is taking hold across the country. Only 3 affordable homes for sale in Cambridge; 9 in Warwick; and just 1 in Brighton & Hove.
In Exeter only 1% of homes on the market are affordable, Shelter said; while in South Lakeland in the north west it's 4%, rising to just 5% in Herefordshire.
Campbell Robb, chief executive of Shelter, said: "When a family looking to buy their first home searches a whole town for a place to live and finds nothing they can afford, it's clear we're not just facing a housing shortage any more: it's a full-blown drought."
Shelter is calling on politicians to build more affordable homes, to put the chance of a stable home back in reach of working families.
But some housing analysts claim that the Shelter campaign is misguided. Henry Pryor, independent buying agent and property expert, said: "Shelter does a huge amount to highlight the plight of those unable to get access to decent housing but this latest report is below its usual high standards. The idea that a significant proportion of homes for sale should be 'affordable' for those trying to clamber onto the housing ladder is both naive and disingenuous.
"The number of people buying homes is up 10% on last year. They may not all be first-time buyers, but what they are buying is demonstrably 'affordable'. At the turn of the last century there were 7.7 million homes across the country. Today we have over 25 million.
"There isn't enough and there is unlikely ever to be enough of the right housing in the right place for the right money. Shelter is right, only politicians can build more homes. But if I were to knock on your door in 316 days time and tell you: 'My party is going to build a serious number of new homes and solve the nations housing crisis. Sadly in doing so we may spoil the view from your home and by definition, to make these homes affordable we will reduce the value of yours. Can I count on your vote?'
"Having a home is rapidly becoming something that certain people suggest is a right. I respectfully disagree. You can bleat about 'rights' all you like but the electorate next spring aren't going to vote for a party who tells them they have to give up their quality of life and rob them (as they would see it) of some of the value of their house just because Sarah (32, who features in Shelter's latest adverts) wants to live near those she loves."