Low-wage single people will spend an average of 43% of their income remaining after housing bills on energy costs.
It means Chancellor Rishi Sunak’s support for gas and electricity costs will provide cold comfort as prices soar in April, campaigners say.
Their research also reveals that low-income single-parent families will forego just over a fifth of income on energy bills after other bills are paid.
It also shows that low-income families will spend 16% after housing costs on energy, compared to 5% for middle-class families.
The Joseph Rowntree Foundation’s cost of living analysis highlights the struggle even after the government’s £200 refund and council tax refund of £150 for people in groups A-D.
The energy price cap will rise by £693 a year to £1,971 from April for millions.
Katie Schmuecker, Rowntree’s deputy policy director, said: ‘These families stand to find at least half of the eye-popping increases in energy bills, when many are already going into debt to keep their homes warm and food on the table.”
Ministers are under pressure to drop green levies as the Labor Party says it would scrap VAT on household energy bills for a year.
The Treasury said: “We understand that people are worried. . . That’s why the Chancellor announced a £9billion package to protect millions of households from the impact of rising global energy prices.