A poll of 3312 people, conducted by pollsters ReachTEL on January 25 and commissioned by the Stop Adani Alliance, found 65.1 per cent of Australians opposed or strongly opposed Indian mining company Adani building the new coal mine in Queensland.

The figure represents a 13.2 per cent rise - from 51.9 per cent - in opposition to the project compared to March 2017. Significantly, the latest poll found an outright majority of Nationals (55.3 per cent), One Nation (52.9 per cent), Labor (75.6 per cent) and Greens (94.2 per cent) voters all oppose the mine.

More Liberal voters (43.2 per cent) said they opposed or strongly opposed the project compared to 34.7 per cent who said they supported or strongly supported it.

The findings come a day after Mr Shorten told the National Press Club the project had to stack up commercially and environmentally for federal Labor to support it, and that more needed to be done to protect the Great Barrier Reef, which environmental groups warn will be negatively impacted by the project.

"If it doesn't stack up commercially or if it doesn't stack up environmentally, it will absolutely not receive our support," Mr Shorten said.

The comment has been interpreted as a signal the federal opposition is considering formally opposing the project.

Internally, Labor's shadow cabinet has discussed whether to oppose the project and Mr Shorten has promised a decision before the next election, which is due in the next 18 months.

Labor MPs say there is deep unease in the caucus about the project going ahead, but even those who oppose the project admit it may not be possible for the federal opposition to stop the mine because environmental approval has already been granted and it cannot influence the decision on whether federal assistance through the Northern Australian Infrastructure Facility will be granted.

Symbolically, however, formal opposition from one of the two major political parties to the project would be a blow.

"We haven’t decided where we land on this, but Bill has heard the deep community concern," a senior MP said.

That MP played down suggestions Labor was weighing a shift in its position because of pressure from environmental groups on Victorian MP David Feeney, who is facing a byelection in his seat and a difficult campaign against the Greens.

The polling also showed 73.5 per cent support for stopping the expansion of all coal mining and accelerating the construction of solar power and storage to reduce the threat of climate change.

Australian Conservation Foundation chief executive Kelly O’Shanassy said the poll showed  opposition to the coal mine was growing and was a reminder our to MPs that "they must listen to the will of the people and chart a course from our dirty coal fuelled present to a clean energy powered future".

“We are encouraged by the comments of Opposition Leader Bill Shorten yesterday [Tuesday] that the ALP is scrutinising the merits of the dirty Adani project. Mr Shorten is right, you can’t have it both ways on climate change," she said.

"He should reject the mine. A clear rejection of the mine and a pledge to stop it would be Mr Shorten’s Franklin River moment."

If it goes ahead the mine would be Australia's - and one of the world's - largest coal mine.