Former prime minister Scott Morrison – who also secretly held the portfolios of health, finance, home affairs, treasury, industry, science, energy and resources during his time in office – defended his actions on Wednesday, staring down calls for him to leave Parliament.

Prime Minister Anthony Albanese revealed on Tuesday that Morrison had secretly taken on ministerial responsibilities for five departments.

Then-treasurer Josh Frydenberg, who was also deputy Liberal leader and spent months living at the Lodge with Morrison during the pandemic, only discovered the subterfuge this week.

Morrison had secretly taken on responsibilities for the treasury portfolio less than a week before the May 2021 budget.

Former Home Affairs Minister Karen Andrews, who also discovered the news this week, was among those who called for Morrison to resign.

But in a highly charged press conference, Morrison defended his actions, saying he acted with the interests of Australians front of mind at all times.

Today on Please Explain, columnist and senior reporter Jacqueline Maley joins Bianca Hall to discuss what could have motivated Morrison, the former "minister for everything".