Assistant Treasurer Stuart Robert has confused Australia's debt with its deficit, underquoting how much the country owes by a cool $332 billion.
Mr Robert made the embarrassing mistake on Thursday as he attempted to sing the government's praises for financial management.
"We saw a great result reflecting on the 17/18 financial year. Literally a $19.3 billion turnaround to the lowest debt in 10 years at $10.1 billion," he told Sky News.
Net debt was $342 billion in the latest figures.
According to the final budget outcome released on Tuesday, the deficit in 2017/18 was $10.1 billion in the year, or 0.6 per cent of gross domestic product.
That's a $19.3 billion improvement on the deficit originally estimated for the period.
Labor's finance spokesman Jim Chalmers pounced on Mr Robert's "extraordinary gaffe".
"Is it any wonder Scott Morrison describes his own government as a Muppet show when you have a treasury minister who can't even tell the difference between debt and deficit?" Mr Chalmers said.
"Somebody needs to tell the poor fellow that is the deficit number, the $10 billion. Debt is actually at record highs."
Mr Robert was coy on whether the extra government revenue would be directed into matching Labor's income tax cuts.
"Let's not get ahead of ourselves. Our job is to govern sensibly, wisely and you've seen that with the 17/18 numbers coming out," he said.
