Despite hefty interest rate cuts, increasing numbers of borrowers are struggling to meet their mortgage repayments, according to Fitch Ratings.

Repaying a variable loan has become cheaper over the last 12 months, but Fitch has reported that the national share of mortgages that had become delinquent rose from 1.2% to 1.45%.

‘‘The Reserve Bank of Australia’s decision to reduce the cash rate did not have a positive impact on mortgage performance in the six months to end-March 2013, in contrast to the six months to end-September 2012,’’ said the Fitch report.

The Fairfield-Liverpool region of Sydney had the highest share of borrowers who were more than 30 days behind on their mortgage, after its delinquency rate rose from 1.82% to 2.37%.

The NSW Central Coast had the next highest share of missed repayments, followed by the Gold Coast, Caboolture Shire in Queensland, and outer south-western Sydney.

The best-performing regions were Boroondara City in Melbourne, south-east inner Brisbane and Sydney’s lower North Shore.

Areas that suffer most from mortgage stress tend to have higher rates of unemployment and lower average household incomes.

Fitch said the slump in south-western Sydney suggested there was a limit to how much cutting interest rates could do to prevent people falling behind on their repayments and delinquency rates may have hit a ‘virtual floor’ late last year.