Independent analysis pointing to a $51-billion black hole in the Abbott government budget is wrong, says Treasurer Joe Hockey, after earlier on Tuesday declining to deny the figure.

The Treasurer changed his tune in an afternoon radio interview with Sydney station 2GB after earlier on Tuesday failing to refute the figure when it was put to him in an interview with Adelaide radio 5AA.

Treasurer Joe Hockey has changed his tune over a forecast $51 billion budget black hole, saying the figure is wrong. Credit:Alex Ellinghausen

"The figure is wrong," Mr Hockey told 2GB, while refusing to provide any further insight into the government's budget forecasts. "I am confident it's not going to be around that mark."

He said the government was still finalising its numbers for the mid-year budget update in December and was waiting on ABS data that would be released.