National says Treasury's failure to front at Tuesday's Epidemic Response Committee is unacceptable, and is another example of the government's arrogance and dismissal of scrutiny.
Treasury Secretary Caralee McLiesh was due to appear on Tuesday morning to discuss the Budget, and Treasury's forecasts, but pulled out because she was unwell and no other executive with responsibility for the Budget was available.
It follows Finance Minister Grant Robertson withdrawing from the committee at the last minute last week, and a memo from the Prime Minister's office to Ministers to "dismiss" media requests about a Covid-19 document dump.
But Treasury and the Prime Minister say this is just a case of illness and bad timing.
Political reporter Yvette McCullough has more.