A £500m-plus revamp of the Child Support Agency three years ago has failed to produce any significant imp-rovement in performance, the National Audit Office said yesterday, with the agency "continuing to fail many parents and children in a big way".

The government seems not to have learnt lessons from child support systems elsewhere in the world, all of which have the power to take money from the wages of non-paying parents, ra-ther than relying on direct payments and debt collection, said the NAO.