'Jobs growth at risk' if budget fails

Treasurer Joe Hockey is very confident of getting his second budget through parliament, warning that if it doesn't, jobs will be at risk.

Mr Hockey says his May 12 budget will focus on jobs and growth.

"If Labor votes against this next budget, they are voting against job creation," he told Adelaide radio station 5AA.

The budget will continue to try to rein in unsustainable spending, but it won't happen in "one event".

"It's going to take years but we need the support of others."

Mr Hockey earlier acknowledged there was a risk the government could lose its triple-A credit rating if it doesn't get spending under control.

"The triple-A credit rating is safe for so long as we have a credible trajectory back to the point where we live within our means," he told ABC radio.

The treasurer denied that Australia was on "credit watch".

The head of the government's financial system inquiry David Murray believes the rating is at risk due to a deteriorating budget, and the country's banks need to prepare for the fallout.

"The AAA rating of the Commonwealth is looking increasingly vulnerable, with little room to move," he said.