At the same time, SVRs have held steady at between 3.6pc and 4.6pc over the past decade, even as initial rates on mortgages have plunged, making the test tougher than was initially expected.

As a result, the Bank of England is looking at softening the affordability check, potentially reducing the additional interest rate charge from its current level of three percentage points.

Martin Beck at the EY Item Club said the move would be “odd given how loose mortgage lending has been – it has not been hard to get a loan”.

But he added that changing the rules after the stamp duty holiday has ended means officials are “not adding fuel to the fire; they are supporting the market at a time when headwinds are building”.

Kallum Pickering at Berenberg Bank said changing the rules could be proportionate, as banks have built up larger capital buffers in the years since the financial crisis, meaning they can withstand losses from risky loans without cutting back on lending to the rest of the economy.

At the same time, households are not heavily indebted by historic standards, with many building up significant savings over Covid lockdowns.

David Hollingworth, at brokerage L&C Mortgages, said the rules bite particularly for first-time buyers who typically have to accumulate a large deposit and then stretch to get a large mortgage to get onto the housing ladder.

Officials are also reviewing the rule which limits lending to buyers borrowing more than 4.5-times their income.

Currently such large loans can make up no more than 15pc of a bank’s total loanbook.

The Bank of England declined to comment.