It is a long way from policy idea to a new law, but sometimes the process is so stealthy that no one notices until it is too late. I am therefore flagging up a proposal for paying for parks and open spaces apparently being discussed by ministers. It comes from the influential think-tank Policy Exchange.

They suggest that people living near parks, and whose houses increase in value because of this, should pay extra tax to contribute to the upkeep of the parks. (This is called hypothecation, and is rare here, although it is common in the USA.) The idea has arisen because parks and open spaces are facing one of their periodic funding squeezes. This happens when local councils have to cut their budgets, as much of this spending is discretionary and therefore at risk. By the time councils have paid for all the things which they have to do there is precious little left for the things that they might do. Birmingham City Council has recently gone through this painful process.

The last time that this happened, in the 1980s, parks were starved of staff and funding and subjected to minimal and damaging contract management. Many became derelict no-go areas for their local communities. Since the 1990s money has been available again, for example through the National Lottery, Landfill Tax (one of the rare hypothecated taxes we do have) and more generous public spending budgets.

The Policy Exchange looks at the looming problem from the wrong perspective. Ignoring the impossible bureaucracy which the implementation of their idea would need, the key issue is the discretionary nature of spending on parks, local nature reserves and other open spaces, despite a mountain of evidence about their health, environmental and nature conservation benefits. The solution is to make their provision and management a statutory obligation so that it would have to be part of every council’s budget.

The Policy Exchange claims that their idea would ensure local support and involvement in the care of parks and other amenities. They have obviously not noticed that there is already an army of friends, neighbourhood, campaign and self-help groups involved. Taxing the neighbours is unlikely to increase this participation, it is more likely to cause resentment and conflict and lead to poor management.