Federal Labor MPs have been given new legal advice arguing there is a valid pathway to revoke the environmental approvals for the controversial Adani coal project, and a summary of polling showing stopping the project would not necessarily cost seats in central Queensland.

Guardian Australia has seen a brief for Labor MPs prepared by the Stop Adani campaign, which quotes legal advice from Neil Williams SC, a specialist in environmental and planning law, arguing “there is evidence to support revocation of Adani’s approval under section 145 of the Environment Protection and Biodiversity Conservation Act, including significant impacts on water resources that were not assessed when the mine was approved”.

The legal advice, according to the brief circulated to MPs and members of the shadow cabinet, says the environment minister could revoke the approval on the grounds that there is new information about significant negative impacts from the mine – namely the impacts on water, and on the habitat of the black‑throated finch.

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It contends that pathway could allow a revocation of Adani’s approvals without triggering compensation risks.

That opinion builds on legal advice the Australian Conservation Foundation shared with Bill Shorten early last year. The ACF opinion argues that the commonwealth environment minister has discretion to revoke the Environment Protection and Biodiversity Conservation Act approval for Adani “on at least two grounds”.

The first ground would be “new information of the consecutive bleaching of the Great Barrier Reef, indicating increased sensitivity to greenhouse gas emissions” and the second would be “new information of the insufficiency of offsets for the endangered black-throated finch, indicating a threat to the continued survival of the species from the Carmichael project”.

The brief from the Stop Adani campaign also refers to polling in three central Queensland seats: Capricornia, Herbert and Dawson. It claims the polling shows that 60‑70% of residents support action on Adani on water grounds.

It says polling of 800‑900 voters in the three seats undertaken last October pointed to “strong support” for reviewing the environmental approvals for the mine. “The results also show that a large number of minor party voters are supportive of action, including those who intend to vote for the Katter Australia Party and One Nation.”

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Adani has flared again as a political issue for Labor because key unions have made public interventions over the past week arguing that the project should be supported by the Queensland Labor government – interventions that have been leapt on by Coalition frontbenchers who see an opportunity to bolster the Morrison government’s political position in central Queensland in the coming election.

While the government is blasting Labor from a pro-coal, pro-jobs position, Labor is also under sustained pressure from the environment movement, the Greens and progressive activist groups to toughen its stance against a project which has become a proxy for action on climate change in the national political debate.

The brief to Labor MPs from the Stop Adani campaign says the group is looking for a commitment that “if elected, we will review the federal environmental approval and if the evidence supports it, we will not hesitate to revoke it”.

Over the weekend, Labor’s environment spokesman, Tony Burke, said he was not in a position to make any commitment about future action Labor might take because if the decision was reviewed, he was potentially the decision maker.

Burke told the ABC on Sunday he had always been sceptical about whether the law has been followed in relation to previous environmental approvals for the Adani project, but he argued he could not telegraph a firm disposition about what he might do about the approvals in the future without making a prejudgment that could render any subsequent decision unlawful.

In explaining his stance, Burke referred to a long-running saga in the 2000s in which a Liberal environment minister had to overturn his own decision to block a $220m windfarm project to save orange-bellied parrots after a federal court appeal.

Shorten signalled publicly, and privately to environmental activists at the start of 2018, that federal Labor was looking to toughen its position against the controversial project, but the Labor leader ultimately pulled back from that shift largely due to internal concerns about the political fallout in central Queensland.