Seed national coordinator Larissa Baldwin told NITV it was "ridiculous" that Westpac, named the world’s most sustainable company in 2014 by research company Corporate Knights, was not willing to rule out funding the $16.5-billion project set for development in Queensland’s Galilee Basin.
"If Westpac was really committed to social and environmental responsibilities, it would not support this," she said.
When NITV asked Westpac to confirm its position on whether it would support Adani, it replied: "While Westpac does not comment on matters relating to specific companies or projects, we assess all transactions through a sustainability risk lens as part of our normal credit risk procedures.
"We apply additional scrutiny to project finance transactions, including applying independent due diligence, as part of our commitment to the equator principles."
"If Westpac was really committed to social and environmental responsibilities, it would not support this"
The equator principles, which Westpac has signed, are a framework for assessing the environmental and social risk of projects.
Seed has been calling on Australia's big four banks to say "no" to financially supporting the mega mine that is expected to produce 60 million tonnes of coal per annum over 60 years.
While a Commonwealth Bank spokesperson told NITV the bank's "advisory mandate with Adani" had "ended", it did not specify if it would refuse financing the Carmichael project in the future. ANZ also did not confirm its stance.
The National Australia Bank is the country's only financial institution to pledge it will not affiliate with Adani. It told NITV it "is not involved and has no plans to be involved in any financing of the Carmichael coal mine".
A total of 11 European and US banks, including Goldman Sachs, JP Morgan Chase and Citibank, have already pulled out of the controversial project, citing ecological impacts.
Adani suffered a blow in August when the Federal Court overturned approval of the mine, but it was given the green light "subject to 36 strict conditions" by Environment Minister Greg Hunt in mid-October.
The conditions "will ensure the proponent meets the highest environmental standards and that all impacts, including cumulative impacts, are avoided, mitigated or offset," he told media.
However, Australian Conservation Foundation chief executive officer Kelly O'Shanassy said the government had given Adani too much discretion.
"They could potentially alter wildlife protection and habitat rehabilitation measures, chose not to publish monitoring data or shift the locations at which it is supposed to monitor the mine's impact on groundwater," she said in a statement.
Indigenous elders have also expressed their disapproval of the project.
South Australian Aboriginal Justice Advisory Committee leader Tauto Sansbury, who advocates for Indigenous rights across the nation, said the project would considerably impact Australia's Indigenous peoples.
"People are fearful of losing their homes, losing their connection to the land as well as culture because once you remove somebody from a place and put them somewhere else then you," Mr Sansbury said in the season-starter episode of NITV's Awaken program.
"Staying on country is really important for the next generation."