In the next few days it is expected that 51 much-loved mature horse chestnut trees on an avenue on Tooting Common will be felled and replaced by Wandsworth Council.
The council has said they are diseased, rotten and a safety risk, and plan to replace them with 64 semi-mature lime trees.
But that is vehemently denied by independent tree consultant Jeremy Barrell and local campaigners who are fighting to save them. They say the trees just need maintenance.
Campaigners say this boils down to money and the council are getting Heritage Lottery cash to replace the trees which will cut the maintenance bill.
The council say lime trees will be much more in keeping with the local area.
What this dispute does highlight are the many political fault lines running through local environmental policy.
Tooting Common is a wide, beautiful well-used open space and it used to be in the constituency of the current Labour Mayor, Sadiq Khan.
One of his flagship green policies is he wants London to be a National Park Garden City and he also wants to increase the tree canopy by 10%.
If the trees are healthy - and the tree consultant says they are - chopping down mature trees does not fit with that policy.
But politically the structures mean the mayor has very little, if no, sway over the cutting down of these trees, which are under the jurisdiction of the Conservative Wandsworth Council.
The mayor's office at the moment will not say anything about this dispute.
In fact, the local Labour MP, Dr Rosena Allin-Khan, has written to the Secretary of State for Communities & Local Government Sajid Javid, to try and get him to intervene. So far he hasn't.
When the chainsaws start up, you can expect protests from local people.
The council says it's public consultation shows support for the plan while campaigners say the consultation was flawed and their local authority is not listening to them.
What it also shows is the devolved strategic policy and power of the mayor can be toothless at a very local level.