The Centrelink automated debt notices scheme is the result of years of cuts to the Department of Human Services by both Coalition and Labor governments, according to the public sector union.

A Senate committee investigating the government's botched Centrelink debt notices system has been told this morning in its first hearing on the matter that far from resulting in a cost saving for the government as intended, the scheme has forced Centrelink staff to do more work under more pressure to resolve incorrect debt notices issued by the system.