Families will take until next summer to pay off their Christmas debts amid falling wages and lower savings, a study has shown.
The TUC said adults face festive debts of £685, taking 24 weeks to pay back the money - four weeks longer than last year.
Workers on the national minimum wage would take a year to pay off a similar amount, said the union organisation.
Its report said British workers were suffering the longest real-wage squeeze since the 1870s, with inflation rising faster than pay for the last 42 months.
TUC general secretary Frances O'Grady said: "Britain's real-wage squeeze is forcing more and more families to put Christmas on credit.
"Millions of households will be still be paying for this year's presents, food and drink well into the summer and beyond.
"Instead of benefiting from Britain's economic recovery, ordinary people are finding it harder to pay off their debts.
"Unless the Government does more to tackle the cost-of-living crisis, this debt bubble will continue to grow. Britain needs a pay rise."