Eight million people are estimated to be just one month's salary away from struggling to pay for their home, a charity has warned.
Some 35% of workers, equating to around 8.6 million Britons, do not have enough savings put by to cover their rent or mortgage for more than a month if they lost their job, Shelter found.
Almost one fifth (18%) of working adults who pay for their housing costs said that if they lost their job and were unable to secure another one right away, they would not have enough cash saved to pay their rent or mortgage at all.
Four in 10 (43%) of those questioned who have children said that they do not have enough money put away to pay for their home for more than a month and nearly one quarter (23%) would be unable to meet their payments at all out of their savings alone.
Shelter said it is bracing itself for a "surge in demand" from people whose budgets have tightened as a recent round of benefit changes kicks in.
Campbell Robb, chief executive of Shelter, said: "These figures paint an alarming picture of a nation where the buffer between having a home and potentially becoming homeless is a single pay cheque.
"The depth of the financial pressure and insecurity felt by people across the country means that millions are living on the edge of a crisis, only secure in their homes for a matter of weeks...
"More and more people are coming to Shelter desperate for advice on how they can stay in their homes, and our services are straining to meet the demand. Anyone who can't meet the payments on their home should seek advice as a matter of urgency."
More than 2,000 people who pay rent or a mortgage and are in employment took part in the survey last month.
A Department for Communities and Local Government spokesman said: "While figures from the Council of Mortgage Lenders show repossessions at a five-year low and falling, we are not complacent and would urge anyone facing financial difficulties to seek early help to avoid losing their home.
"We have one of the strongest safety nets in the world against homelessness, bolstered by £470million Government cash, and extra flexibility for councils to help those in need.
"We've also put help in place including the extended £221million Mortgage Rescue Scheme, and funding for organisations including Shelter to provide information and advice services."