An influential green group is seeking concrete commitments from the major parties and potential crossbenchers for an overhaul of environmental protection laws and the establishment of new independent regulatory agencies, before Australians cast their votes on 18 May.

Lyndon Schneiders, the national campaigns director of the Wilderness Society, wrote widely to politicians on Monday seeking agreement to an ambitious legislative and regulatory overhaul – but the hurry up is directed predominantly at Labor, which has offered an in-principle commitment but has not yet produced a final policy, and the people likely to form the crossbench in the next parliament.

The campaign intervention, which follows significant controversy over a rushed environmental approval for the controversial Adani coal project which the Morrison government ticked off just before calling the election, comes as the green group has amassed a campaign war chest of $400,000 from members and supporters, allowing it to run substantial field operations in targeted seats.

The society is pursuing billboard advertising in Flinders, Reid, Bonner, Kooyong, Warringah and Boothby, with cinema advertising booked in those electorates. It will also fund digital ads in Bonner, Reid, Warringah, Kooyong, Boothby, Flinders, Wentworth, Mayo, Corangamite and Page.

It is also running field campaigns in two marginal seats – Bonner and Reid – with 12,000 voters already contacted, and a target of 29,000. The group is concentrating efforts in areas where voters are more likely to be willing to change their vote over environmental issues.

After some pre-event controversy, Bill Shorten committed at last December’s national conference to introducing a new Australian environment act and creating a commonwealth environmental protection agency if Labor wins the coming election. But the opposition has not yet produced its detailed policy.

In Monday’s letter, seen by Guardian Australia, Schneiders warns Australia is confronting “an unprecedented environmental crisis” and says “we as a nation have lacked the policy tools and the political will to make a difference”.

Wilderness Society cinema ad.

He asks for explicit commitments to strengthen the assessment and regulatory framework, and notes “as we have seen with the recent Adani groundwater management plan approval, government decision making in respect to the environment lacks transparency and the avenues for community to appeal decisions are extremely limited”.

The letter warns the Wilderness Society “will be informing our members and supporters, and voters in key areas, about the environmental policies of parties and candidates. We will be looking at both the commitments themselves, and also whether or not there is a credible pathway proposed to deliver them”.

“Our baseline for assessing success is whether or not the policy framework will turn around Australia’s environment crisis. This is not the same as assessing whether or not the policies are an improvement on the status quo.”

Shorten delivered the commitments at national conference in response to a lobbying effort by Labor’s Environment Action Network (Lean), an internal grassroots lobby group.

The policy shift was endorsed by 498 local branches before the event, and since the conference last December, 77 branches have passed a motion calling on Labor to deliver “a full election policy announcement to underpin this major reform as a high priority for the first term of a Labor federal government”.

The national convener of Lean, Felicity Wade, has also called on the ALP to make good the national conference commitment. “Thousands of party members celebrated when Bill Shorten committed to re-embracing federal leadership on environment at conference last year.

“It was powerful and visionary stuff, a reclaiming of the Hawke legacy when Labor really led in this sphere,” Wade said.

“The scorching summer, dead fish and formal declaration of an extinction have just rammed home the problem since. The party faithful would love to hear Bill’s commitment restated, as would voters who want Australia’s natural environment better protected.”