As far as parties go, it sounded like a big one. In July 2012 green activists organised a “Lizard’s Revenge protestacular” at BHP Billiton’s Olympic Dam uranium mine site.

The pictures show the more than 500 “brave souls” sure seemed to have a good time — except possibly for those poor souls who got arrested.

Nothing to worry about though, the greenies had a plan. They put out a call to supporters after the event: “To support arrestees, please make a tax-deductible donation …” Thankfully the protest event even had its own bank account in the name “Lizard’s Revenge”.

On my weekends I would prefer to ride in a golf buggy than in the back of a paddy wagon, but each to their own. Then again, I don’t expect anyone to make a tax-deductible donation towards my green fees.

Greenpeace, another recipient of tax-deductible gifts, was recently asked on radio, “That range of tactics includes breaking the law?” Its response was emphatic: “Absolutely, when necessary.” In a submission to the Australian government a few years ago, Greenpeace justified such illegal activities by arguing they “have never been for any purpose except the public benefit”.

How did we end up in a situation where self-appointed environmental organisations get to decide when a breach of the law is in the “public benefit”, then ask for tax deductions to fund their self-described philanthropic, unlawful acts?

Under the Income Tax Assessment Act some organisations can apply to be placed on the Register of Environmental Organisations, providing their purpose is to protect or enhance the natural environment, or to provide inform­ation, education or research on the natural environment.

Donors to registered organisations can receive a tax deduction for the donations they make. About 600 environmental organisations are registered and more than $100 million of donations are made to these organisations every year.

Most registered organisations are focused on practical actions to protect and improve the natural environment.

However, more than 100 of these organisations would appear to be more focused on campaigning for political change than directly helping the environment. Such activities have increased. In recent state elections, some organisations asked for tax-deductible donations so they could fund ‘‘doorknockers’’ targeting marginal seats.

Reviewing the scores of how-to-vote cards distributed by these organisations is like listening to variations on a theme — in e-flat: dead possums, dead koalas, turtles, dark clouds, traffic lights and stars. How many different ways can we rank Greens first, Labor second and Liberal-Nationals last?

I have examined the activities of more than 100 of these organisations. More than 80 per cent of them have promoted or been involved in demonstrations, and half support divestment initiatives or legal action against certain develop­ments.

At least 12 per cent of organisations have been involved in unlawful activities of some form. The activities of these groups have moved away from the original purpose of the register.

The trends in Australia have been observed in other countries too. New Zealand, Canada, the US and Britain have all recently taken steps to address the gap between the stated purpose of some organisations and their activities.

We should consider adopting some of the overseas approaches, which include prohibiting: unlawful activities; the soliciting of donations to pay for fines; the making of demonstrably misleading statements; and supporting or opposing political parties or candidates. Greater transparency on the activities of registered organisations and enforcement of existing regulations is needed too.

A current House of Representatives inquiry into environmental organisations eligible to receive tax-deductible gifts is considering these issues.

At the heart of this issue is an imbalance in our democracy. Some of these organisations are highly active in political debates such as what size coal industry we should have, should we irrigate northern Australia and should we permit further tourism developments on the Great Barrier Reef. Some have also tried to influence the decision of UNESCO on the potential listing of the reef as “in danger”, using misleading advertising about the health of the reef.

These are all legitimate policy debates but our democracy will be weaker if one side of the debate can have its voice amplified through generous tax treatment.

However public-spirited the man in the koala suit may think he is, he deserves no louder voice than the man in the hi-vis shirt or the man in the Akubra. It’s time tax concessions for the environment should return to funding actions of practical benefit to the environment, not to fund partisan political debate.

This article was first published in The Australian on July 9 2015.