A new survey has found one in five property owners say they’d find themselves in severe mortgage stress if their monthly home loan repayments are increased.

The Reserve Bank of Australia has flagged it may soon have to lift the cash rate from its emergency rate of three per cent.

Economists say the cash rate could increase to five per cent over the next 18 months .. which would increase monthly mortgage repayments by 450 dollars a month on an average 340-thousand dollar mortgage.

The Loan Market Group’s online survey of 600 people has found 19 per cent of respondents said any increase in interest rates would push them over the limit.

It found 38 per cent could only afford to pay 250 dollars a month more .. while 27 per cent said they’d be able to pay up to 500 dollars.

Only 16 per cent said they could afford over $500 more a month.

AAP