Low-income Australians receiving housing support and other welfare services have joined summer criticism of Centrelink, as the agency faces sustained questions about its new automated debt recovery processes.

Welfare recipients who received debt demands for thousands of dollars during the Christmas and New Year period have questioned new automated data-matching systems introduced in July, a key tool as the federal government pursues efforts to recover millions in unnecessary welfare costs.

Centrelink's automated debt recovery processes have caused controversy over the Christmas period.

Labor last week joined calls for the automated debt-recovery methods to be halted or scrapped. Changes to compliance processes see welfare records matched with other government data, including reported income information collected by the Australian Tax Office.

A new "Not My Debt" social media campaign has seen dozens of recipients of letters of demand highlight examples of Centrelink seeking repayment of thousands of dollars for a range of welfare services, including disability support pensions and Youth Allowance, despite recipients being eligible for the payments.