The biggest risk to Australia's economy is re-electing a Labor government, shadow treasurer Joe Hockey says.

The budget and economic forecasts in the Pre-election Economic and Fiscal Outlook (PEFO) released on Tuesday are almost identical to those in the government's August 2 economic update.

So Mr Hockey focused on commentary in the document outlining the international risks posed to the projections from the Treasury and Finance departments.

"The downside risks are substantial," he told reporters in Melbourne.

"These need to be carefully considered by the coalition."

The risks include the unresolved crisis in the eurozone, anxiety in financial markets about the unwinding of US monetary policy, lingering concerns about the recovery in Japan and economic developments in China.

"These are some of the risks, but overwhelmingly the greatest risk is obviously the re-election of a bad Labor government," Mr Hockey said.