First-time buyers are paying almost twice what they did four years ago for their mortgages, according to new figures.
Data from Abbey Mortgages reveals that the average person buying a house for the first time takes out a loan of £130,000, compared with £75,000 in 2003.
And 53 per cent are borrowing more than £150,000, the study indicates, up from 16 per cent who borrowed that amount four years ago.
Nici Audhlam Gardiner, head of mortgages at Abbey, said that people determined to get on the property ladder are increasingly obliged to take on high levels of debt.
"We are fully aware of the difficulties first time buyers have in getting onto the property ladder," she said.
"Our research shows that they have to borrow more and more to get even a small foot on the ladder."
Recently, market analyst Datamonitor raised concerns about the sub-prime mortgage market in the UK, which rose 28 per cent during 2006 to reach £24.6 billion.