Homeowners could face mortgage hikes of up to £14,000 a year as they come off low fixed-rate deals, adding to the squeeze on living standards, Labour has said.
Analysis by the party shows predicted annual increases in costs for a median house purchase at 80% mortgage in every constituency in the UK.
London seats top the ranking, with the highest rises expected in Kensington, where costs are set to soar by £13,980.
The cities of London and Westminster, and then Chelsea and Fulham come next, with possible rises of £11,730 and £11,480 respectively.
Richmond Park could see mortgages go up by £9,040, Hampstead and Kilburn by £8,740 and Westminster North by £8,450, according to the analysis.
Further down the list, Sheffield Hallam is predicted to see mortgages rise by £3,080, North East Derbyshire by £2,070, and Plymouth, Sutton and Devonport by £1,850.
Homeowners in Rhondda and Easington are to see the lowest increases, at £1,030 and £910 respectively.
Shadow chancellor Rachel Reeves said: “The Tory mortgage penalty is devastating for family finances and is holding back our economy.
“The country is buckling under 13 years of Conservative mismanagement, and it’s families being asked to pay more on their mortgage once again.
“People are asking themselves whether they or their family are better off under the Tories. The answer is no.
“By stabilising the economy, making it stronger and getting it growing, Labour will stop us lurching from crisis to crisis, and make Britain thrive again.”
Ms Reeves is due to visit estate agents in Finchley and Golders Green on Thursday – where the cost of a typical mortgage will go up by £7,490 a year – to discuss how soaring mortgages are impacting the business, homeowners and buyers.
The Office for National Statistics has predicted more than 1.4 million households are facing the prospect of interest rate rises when they renew their fixed-rate mortgages this year.
A string of Bank of England base rate hikes have taken place over the past year, but borrowers on fixed-rate mortgages were cushioned from their immediate impact. Some may get a shock when they come to renew.