Scott Morrison is eyeing a national roll out of the cashless debit card as part of a self-described "compassionate conservative" welfare agenda but says he is prepared to be patient to ensure communities embrace the program before a nationwide expansion.

The Prime Minister says the results from the program's trials - which quarantines 80 per cent of unemployment and various other welfare payments to prevent them being spent on alcohol, drugs or gambling - are "commending itself for wider application", potentially for an under-30s age group.

Welfare advocates continue to dispute the effects of the program, with the government having commissioned new independent appraisals of the card's impact on communities after the auditor general found its department's evaluations were "inadequate".

In an exclusive interview with The Sunday Age and Sun-Herald, Mr Morrison has also defended his plans to trial drug testing for new job seekers as a justifiable government intervention to "help people get on their feet again".