Nearly three-quarters of mortgage holders are now worried about meeting the cost of rising rates in the coming months, surveys suggest.
The Liberal Democrats, who commissioned the research, said the figures expose the “true horrors” of the crisis facing borrowers.
The party blamed the recent rise in mortgage rates on the government’s “failed and disgraced” mini-budget, which caused turmoil in financial markets, driving up interest rates.
The party is urging ministers to launch a mortgage protection fund in next week’s much-anticipated autumn budget, which would offer struggling households a “lifeline” of up to £300 a month.
The survey, conducted by Savanta ComRes, found that fears about rising mortgage payments are leading to growing cost-of-living anxiety.
The proportion of UK adults with a mortgage who said they were worried about a rise in their rates rose from just over half (55%) last year to nearly three quarters (73%), an 18 point rise percentage.
Those with a mortgage are now more likely to worry about rising housing costs than renters, of whom 64% said they were worried in the latest survey, up five percentage points from last year.
Elsewhere, the proportion of people worried about a rise in their utility bills rose from 73% to 81%, while 77% of UK adults are worried about covering the cost of household items in the next few months, compared to 67% previously.
There was also a nine percentage point increase in those concerned about an increase in fuel payments, from 61% to 70%.
Lib Dem Treasury spokeswoman Sarah Olney said: “These are very worrying figures that show the true horrors of the mortgage crisis.
“The government has set off a mortgage time bomb and it must be defused before families lose their homes.
“Millions are already struggling to pay a Conservative property fine worth hundreds of pounds a month after the government’s failed and failed budget.
“No one should have to worry about having a roof over their head due to the catastrophic incompetence of this Government.
“Ministers are to use next week’s autumn statement to launch a mortgage protection fund, aimed at those most at risk of losing their homes, to offer struggling households a lifeline of up to £300 a month.
“This could be financed by reversing tax cuts for the big banks that make huge profits from sky-high interest rates.”
For the latest figures, Savanta ComRes surveyed 2,236 UK adults online from November 4-6, including 642 who owned their home with a mortgage or loan.
The survey company previously surveyed 2,231 UK adults, also online, from November 5-7, 2021, including 516 home or mortgage loan holders.
Data were weighted to be demographically representative of UK adults.
A government spokesman said: “There are a variety of factors affecting mortgages and interest rates, which have been rising internationally in response to global trends, including (Vladimir) Putin’s illegal invasion of Ukraine.
“The Government has taken immediate steps to ensure the UK’s economic stability and demonstrate its commitment to fiscal discipline, to bring stability to markets, including mortgages.
“The (Financial Conduct Authority) rules require companies to treat customers with payment difficulties fairly.
“More broadly, the Energy Price Guarantee will save the typical household around £700 this winter, based on current price-cap energy prices, cutting bills by around a third, and (we) we are providing payments of £1,200 to the eight million most vulnerable families.”