Unsecured debt in the UK rose to an average of £15,385 per household, totalling a fresh high of £428bn, according to the Trades Union Congress (TUC).
The figures exclude mortgages, but show the average household debt rose £886 in a year.
However, Bank of England figures, which exclude student loans, give a debt total of half the TUC’s estimate.
The Bank of England says growth in consumer credit has been gradually slowing since the end of 2016.
According to the TUC’s figures, Unsecured debt as a share of household income is now 30.4 percent – the highest it’s ever been, and above the level it reached in 2008 ahead of the financial crisis, when it reached 27.5 percent.
The TUC reached its figure for unsecured debt by adding up the total amount owed in bank overdrafts, personal loans, store cards, payday loans and outstanding credit card debts, as well as student loans.
The union said government austerity and years of wage stagnation are the key reasons behind the increase in unsecured debt.
TUC general secretary Frances O’Grady said: “Household debt is at crisis level. Years of austerity and wage stagnation has pushed millions of families deep into the red.
“The government is skating on thin ice by relying on household debt to drive growth. A strong economy needs people spending wages, not credit cards and loans.
“Our economy is not working for workers. They need stronger rights and bargaining powers. Trade unions should be allowed the freedom to enter every workplace to negotiate higher wages.”