An alliance of charities has pointed out that people are being left with “the impossible choice” of heating homes and buying clothes for their children.
The alliance, which is made up of 25 charities, wrote a letter to Prime minister Boris Johnson and chancellor Rishi Sunak, outlining their concerns.
Among the charities who signed the letter seen by Sky News are Greenpeace UK and Save the Children.
Dan Paskins, of Save the Children, said: "The cost-of-living crisis, fuelled by soaring energy prices, is totally unsustainable and is hitting the lowest-income families the hardest.
"Parents we work with tell us that they’re struggling to meet basic needs, leaving them having to make impossible choices between heating their homes and buying clothes for their children, and children are paying the price."
Dr Doug Parr, policy director at Greenpeace UK, added: "The twin imperatives of a gas price crisis and the climate crisis mean we need to get off fossil fuels as fast as we can whilst protecting people on low incomes.
"A windfall tax on oil and gas companies would be a fair way to help finance the transition as we exit fossil fuel production in line with advice from leading experts at the International Energy Agency."
A government spokesperson said: "We recognise people are facing pressures with the cost of living, which is why we are taking action worth more than £4.2 billion and supporting vulnerable households through initiatives such as the £500 million Household Support Fund and Warm Home Discount.
"The Energy Price Cap is currently insulating millions of consumers from high global gas prices. We’ll continue to listen to consumers and businesses on how to manage the costs of energy."