It has yet to be seen how realistic the country's economic projections are, a top economist has said.

Treasury is releasing its fiscal update and Finance Minister Grant Robertson will be releasing his first budget policy statement today.

He said the public will like what they see.

However, ANZ Chief Economist Sharon Zollner told Mike Hosking some of these figures could be up to debate.

"We're expecting Treasury to come out with some pretty optimistic gross numbers which will give the Government the head room Grant Robertson was talking about, but the question is will those hook ups be right?"

LISTEN TO SHARON ZOLLNER TALK WITH MIKE HOSKING ABOVE