One accused whistleblower defends another

A lawyer charged with conspiring to reveal classified information about a diplomatic scandal is representing another man who blew the whistle on alleged war crimes.

Bernard Collaery, who is fighting his own charges under Australia's strict national security laws, has stepped in to help former military lawyer David McBride.

McBride is facing trial in the ACT Supreme Court after leaking classified documents about alleged war crimes in Afghanistan.

He has called on Australians to help fund his legal defence after originally deciding to represent himself.

"I've become convinced the case is bigger than me and these issues need to be properly ventilated," McBride told reporters outside court on Friday.

"It's never been about avoiding jail for me. It's about fighting to improve Australia."

McBride leaked documents to the ABC containing allegations Australian troops had shot unarmed civilians, including children.

He has described the story as a "beat up" and claims he leaked the documents to ensure soldiers are better protected by the government.

His long-running case is due back in court on February 24.

In a separate case, Collaery has been charged with helping lift the lid on a secret 2004 operation, in which Australian spies bugged East Timor's cabinet room during sensitive negotiations about an oil and gas deal.