Federal Labor has questioned the merit of granting a taxpayer-funded loan for a railway to the Adani Carmichael mine.
The Indian company has applied for a $900 million concessional loan from the government's Northern Australia infrastructure fund to help build a rail line connecting the central Queensland mine and the Abbot Point port.
"If you want to have a good commercial operation in Australia, I am not convinced the taxpayer of Australia should underwrite the risk of the project through a billion dollar loan," Opposition Leader Bill Shorten told reporters in Brisbane.
Mr Shorten said other mining companies are not getting billion dollar railways built for them.
"We have to make sure it stacks up," Mr Shorten said.
The company's Carmichael coal mine project in Queensland was approved in December but has faced serious opposition from environmental and indigenous groups.
Senior executives of Adani, including founder and chairman Gautam Adani met with Prime Minister Malcolm Turnbull in India on Monday.
Mr Adani requested an early resolution of native title issues surrounding the mine, which was hit by a Federal Court ruling that invalidated deals with traditional owners across Australia.
Legislation dealing with the problem is before the Senate and Mr Turnbull is understood to have assured the company the issue would be fixed.
Mr Shorten said Attorney General George Brandis was to blame for the confusion over native title.
Anything he touches turns to "custard", the Labor leader said.
"In an incompetent government, he is the gold medal of incompetence," he said.
