The number of Australian homeowners struggling to meet their loan repayments has climbed by more than a third in the past 12 months, as falling affordability and higher rates continue to weigh on their finances.

Fujitsu Consulting's Australian Mortgage Industry Stress-O-Meter revealed that about 70,000 families are now suffering from mortgage stress across the country - a 52% rise from a year ago.

Fujitsu identified Sydney, Melbourne and Perth as having the highest growth of mortgage-stressed households.

Mortgage stress - which is measured by a household's ability to maintain mortgage repayments, fall into arrears and potential defaults - has been rising sharply, with young and growing families experiencing the most pressure. Homeowners in the suburban mainstream are also expected to be hit hard by the rate rise last Wednesday.

"While traditional battlers continue to be hit hard, the extent of mortgage stress and potential problems have now reached mainstream Australia," said Martin North, managing consulting director, Fujitsu Australia. "The results of the 'Stress-O-Meter' are very telling. Specific customer groups are under intense pressure, based on the balance between net income and mortgage repayments. Young growing families are under extreme stress, which has only increased with today's interest rate rise."