The climate change activist movement Extinction Rebellion has been accused of “extremism” by a former counter-terrorism chief.

Richard Walton, who was head of the Metropolitan Police Counter Terrorism Command between 2011-2016, has delivered his verdict not to a newspaper but in a report he co-authored for the right-wing think tank, Policy Exchange — an organisation with a political agenda that scored a transparency rating of zero from the Who Funds You? think tank, and which enjoys often slavish coverage by the British media any time it publishes a Big Thought. (A recent example being the Daily Mail front page reporting on its stop and search report as if it were a government proposal.)

Policy Exchange’s report on Extinction Rebellion has received understandable media attention because of Walton’s former job at Scotland Yard – and the explosive conclusions it draws about the environmental movement.

“The leaders of Extinction Rebellion seek a more subversive agenda” than fighting climate change, says the paper. “One that that is rooted in the political extremism of anarchism, eco-socialism and radical anti-capitalist environmentalism.”

It warns that the group wants to accompany mass protest with “law-breaking – leading eventually to the breakdown of democracy and the state”.

There are two problems here.

The first is that many of Policy Exchange’s seemingly shocking discoveries are in fact descriptions of what Extinction Rebellion has already made publicly known.

One of its tactics is mass civil disobedience. The group is open about that. And with the word “rebellion” in its name, it is clearly a subversive, unconventional group working outside of the normal state structures.

Its activists relish causing disruption – while writing this piece, for example, I received a triumphant press release from them about causing “Motorway Madness” in Bristol, on day three of their “Summer Uprising”. The group celebrates these disturbances and accompanying arrests, viewing them through the same lens as the tactics used by the suffragettes and civil rights movements.

“If we are to have any chance of leaving a liveable planet for the next generation, the existing system needs to change and Extinction Rebellion is determined about its aim to make that happen by whatever non-violent means necessary,” the group states in response to Policy Exchange’s report.

The second problem is that the Policy Exchange paper is part of a longstanding pattern of think tanks weaving a web of policy and lobbying against climate change activism. In that regard, it’s not particularly new.

“The large number of think tanks and think tank networks involved in climate change policy scepticism can be considered central” to the battle over the climate change policy agenda, writes the political scientist Dr Dieter Plehwe in a 2014 paper, “Think tank networks and the knowledge–interest nexus: the case of climate change”.

“The combination of powerful expert, consulting and lobby/advocacy capacities that rely on organised think tank infrastructures implies a growing need for closer attention to think tank models in public policy analysis.”

There’s nothing new in an establishment rattled by a protest group. But it will become increasingly difficult to continue branding climate change activists “extreme” when their cause is becoming ever more mainstream.