The Australian Conservation Foundation has accused the Turnbull government of using the "drug dealers defence" in its support for the Adani coal mine project.
Resources Minister Matt Canavan says the controversial Adani mine should go ahead, because if Australia doesn't supply coal from Queensland to India, other countries will.
The ACF's president Geoff Cousins described the argument as "the drug dealers' defence".
"If we don't supply the drugs, someone else will," Mr Cousins told ABC Radio.
Adani wants 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.
Acting Prime Minister Barnaby Joyce argued giving coal to India would help lift people out of poverty.
"I think we also have a moral responsibility to be part of that solution of delivering power to people who don't have it," he told reporters in Sydney on Thursday.
Mr Joyce said the rail line could be used by other companies.
"It's a loan, so it's paid back. We're not giving Adani money. We're lending them money and we hope to make money on it," Mr Joyce said.
Federal Labor is opposed to the loan, saying taxpayers shouldn't be used as an "ATM for Indian coal mining companies".
