Yorkshire’s Brain Tumour Charity, which supports those diagnosed along with their families, said it has seen a near 50 per cent drop in income due to the crisis.
As gross domestic product (GDP) figures increased just 0.1 per cent in February, the charity’s CEO said the rise in food and energy costs was affecting donations, particularly from mass fundraising events such as marathons.
In a typical year, on average each JustGiving page set up to fundraise for the charity would raise £100, the charity said.
By comparison, the average JustGiving page set up in 2022 is raising just £23 from the same number of donors.
Chief executive Marie Peacock said: “The last two years were horrendous, but at least as a charity we had glimmers of hope during the pandemic, with a range of emergency Covid-19 funding available.
“Now there is no additional support and just when we expected fundraising activities to kickstart again, the cost of living crisis is having a huge impact.
“Individuals are not able to donate or attend events and those undertaking challenges are fearful of asking family and friends for sponsorship.
“Our usual amazing fundraisers are kind and generous people, which means many are, understandably, focusing on activities to raise money for Ukraine at this time.
“The year ahead looks much more unpredictable now and is causing a lot of concern.”
Income at the charity has dropped by 48 per cent, Ms Peacock said, despite demand for its services rocketing 225 per cent during the pandemic.
GDP was expected to rise by 0.3 per cent by economists, with this month’s figures lower than January’s 0.8 per cent growth.
Charities were able to apply for a multitude of schemes during the height of the pandemic including making use of the furlough scheme for staff, and grants administered by the National Lottery.
But the vast majority of extra support put in place has now been wound down as restrictions on public life have lifted.
Labour’s shadow minister for arts and civil society, Barbara Keeley MP said: “Covid demonstrated how essential charities are in a crisis. But just as the cost of living crisis hits and charities will need to step in once again to help, their funding is at risk.
“Between soaring energy and fuel bills and spiralling costs for food, many people will no longer have cash to spare to make regular donations to charities or be able to fundraise from friends and family for sponsored events.
“Labour would tackle the Tory cost of living crisis by cutting energy bills by up to £600, funded by a one-off windfall tax on the excess profits of the oil and gas producers.”