The proportion of prime UK residential mortgages that are three months or more in arrears has more than doubled in the past year, according to new data.

Moody’s, the credit ratings agency, published data yesterday showing that the proportion of mortgages within securitisation vehicles, which are in arrears by 90 days or more, was 0.74% of all loans in the first quarter of 2008. That had jumped to 1.66 % in the first quarter of 2009.

The rise is significant because it shows that the economic downturn is now starting to push up mortgage arrears among mainstream borrowers – as opposed to riskier subprime customers with patchy credit histories.

Financial Times