Debt will last several decades: Costello

It will take several decades for Australia to eliminate government debt, former treasurer Peter Costello says.

Australia's longest-serving treasurer also says budget surpluses will be rare.

Treasurer Joe Hockey will deliver his second budget on Tuesday.

"In my lifetime, I don't think we'll see the Commonwealth - and I'm talking 20 or 30 years - pay off all its debt," Mr Costello told The Australian.

"It's a reflection on the fact that last time to pay off the debt we had to run 10 years of surplus. So, you know, you would have to run at least 10 years of surplus to pay off the debt (today)."

He said the test for Mr Hockey was to demonstrate a clear and credible pathway back to surplus.

Mr Costello was treasurer from 1996 to 2007.