One in 10 UK families – about 3m households – are facing a cost of living crunch this winter, unable to cover even basic bills such as food and heating, according to Citizens Advice.

One in five of all adults had cut back on their food shop or turned off the heating, while one in 10 anticipated having to use food banks, a survey by the consumer charity found.

Citizens Advice urged the government to bring forward its standard inflation-matching uprating of benefits from April to December, arguing this could make the average family on universal credit £30 a month better off.

Without fresh government help it expected to see rising numbers of low-income families coming to its advisers for help over the next few months because of the “triple whammy” of the £20 a week universal credit cut, soaring energy bills and rising inflation.

Dame Clare Moriarty, the chief executive of Citizens Advice, said: “The government has a crucial opportunity to intervene before things escalate even further. We’d urge them to act now and increase benefits in line with inflation this December.”

The government on Wednesday brought into force adjustments to the universal credit taper rate for working claimants, which were announced in the October budget with the promise that nearly 2 million families would be £1,000 a year better off.

But critics have pointed out that the majority of households on universal credit – about 3 million – would see no benefit from the move, including those who cannot work, such as carers, parents of very young children, and sick or disabled people.

Analysis by Citizens Advice found that even when placed on a strict “minimal budget” – the financial plan used by the charity to support clients through a debt management process – more than 3m households were unable to meet basic living costs. A further 400,000 were left with just £50 a month once bills were paid.

Citizens Advice said nearly three-quarters of its frontline advice staff had reported an increase in the number of people coming to them over the past three months unable to afford basics such as rent, food and energy.

“I spoke to one man who said things are so bad he’s keeping warm at night by wearing three jumpers and lying on the sofa with his dog,” said Aasia Majid, an adviser at Citizens Advice Manchester.

The charity cited the case of Gordon (not his real name), a former engineer in his 60s who had to give up work because of spinal cancer in 2019. He has been claiming universal credit as he cannot work and is now £20 a week worse off because of the recent cut.

“I don’t buy the things I need to buy. I’m constantly looking at the bank account,” he said. “I put things off as I can’t afford the petrol to drive. I feel isolated and stressed, but what can I do?”

A government spokesperson said: “We are committed to supporting people on low incomes and the changes we have made to universal credit will see nearly 2 million of the lowest paid better off by around £1,000 a year. The most vulnerable, including those who can’t work, can get additional help with essential costs available through our new £500m support fund.”