Government Services Minister Bill Shorten delivered that scathing appraisal on Wednesday after the former prime minister gave evidence about the unlawful scheme that devastated thousands of Australians.

Mr Morrison was social services minister when robodebt was started and prime minister when it was shut down after a legal challenge.

Robodebt saw an average income figure used to calculate welfare entitlements, which created a number of non-existent debts and wrongly recovered more than $750 million from 381,000 people.

"What we got was peak, vintage Morrison; lecturing, hectoring, not answering questions, splitting hairs on simple yes-no questions ... we've seen him basically say 'I knew nothing, I did nothing, I'm a good person'," Mr Shorten told reporters.

"Scott Morrison had an opportunity to attend the royal commission, personally apologise, accept personal responsibility ... for this massive unlawful scheme.

"The fact the royal commissioner has had to ask him if he's listening at all to the questions, it is almost the sort of television you watch with your fingers over your eyes but you're peaking just to see the next incredibly poor behaviour."

Mr Shorten called on Opposition Leader Peter Dutton to clarify what he'd made of Mr Morrison's display and said the Liberal party appeared "unrepentant".

"It's probably time now for Mr Dutton, who voted to defend Mr Morrison's multiple ministries, who was obviously an enthusiastic cabinet minister approving the unlawful robodebt scheme, to say where does he stand on robodebt?" he said.

"Does he apologise for what's happened, and does he support the evidence of Mr Morrison fully ... is anything Mr Morrison is saying making him feel uncomfortable?"

Mr Shorten said former human services minister Marise Payne had "thrown Mr Morrison under the bus" when she gave evidence on Tuesday, although he added the former PM had "returned the favour" by blaming his colleague.

Australian Associated Press