Around 15 million people are "living on the edge" despite the improving economy, a report by a debt charity has warned.
Stepchange said that these people are either falling behind on bills or are trying to plug gaps in their income by using credit to pay for essential outgoings.
It said that as a result of the high reliance on credit to get by, many people "lack resilience" when it comes to coping with financial shocks - such as a change to their employment situation or the possibility of interest rates rising.
The findings about the continued financial pressure faced by millions of Britons comes as a report by the Trades Union Congress found that most workers on controversial zero-hours contracts earn less than the average wage.
According to the TUC, four out of five workers on zero-hours contracts, deals which do not offer fixed benefits or hours, earn £8.83 on average, much less than the £13.39 earned on average by workers on permanent contracts.
Stepchange estimated that some 13 million people would not have enough savings to last a month if their income dropped by a quarter.
From its findings, it believes that almost three million people are in such a spiral of debt that they are borrowing money just to keep up with their existing credit commitments.
The charity said that credit has become "a distress safety net" for people who fall on hard times.
It said that just one in 10 people believes that relying on welfare would be sufficient to cover essential costs.
The charity said that despite the improving economy, it is still dealing with cries for help from more than 1,000 people every day who are struggling with their finances.
Stepchange's chief executive, Mike O'Connor, said: "Millions of people are living on the edge financially and are not prepared for the future.
"Even with economic growth, consumers are likely to face interest rate rises and increases in costs of essential goods and services.
"Unless we can improve families financial resilience, it is likely that people will be pushed over the edge - often as a result of resorting to high cost credit. We need to act now to address the grave economic and societal problems that come with problem debt."
The charity wants to see a senior government minister taking charge of a national debt strategy.
It also wants all creditors - including utility companies, landlords and council tax collectors - to work together to improve the help they offer to customers in financial difficulties.
Stepchange also wants people to be given sufficient "breathing space" so that those who are already struggling are guaranteed protection from further actions that may worsen their situation, which should include freezing interest and charges.
The report, titled Life On The Edge, based its findings on a YouGov survey of more than 4,000 Britons carried out in December.