Millions of people are out and about during these mid-September weekends. They are visiting stately homes, castles, famous gardens and other historic attractions as part of the Open House initiative in London and the various heritage bodies’ open days in the rest of the UK. It’s Britain’s biggest mass-participation event, and it underlines how much we value the finer aspects of a built environment stretching back 4,000 years — and the landscape in which it stands. William Blake’s great exhortation, to build Jerusalem in this green and pleasant land, may sometimes seem farther away than ever. But at least we can be fiercely protective of the green and pleasant land itself, or what remains of it.

And it has never needed more protecting, because this autumn a new quango — created, symbolically, by the unelected Lord Mandelson — may usher in the biggest change to the landscape in our lifetime.

The quango rejoices in the cumbersome and perhaps deliberately innocuous title of the Infrastructure Planning Commission (IPC). And it was stealthily slipped into last year’s Planning Act without anyone realising how vast would be its power to drive a steamroller through the checks and balances of the current planning system, and through all our cherished notions of local democracy.

What’s behind it? Well, the Government wants to increase renewable energy production and is irritated that wind-farm developers are constantly being delayed, or even thwarted, by challenges from local objectors and conservation groups such as the Campaign for the Protection of Rural England.

So ministers have set up the IPC to wrest large-scale planning decisions — not just about big wind farms, but motorways, airport expansions, power stations, waste-treatment plants and big housing estates — away from local councils and independent inspectors, and instead to decide such matters according to “national policy”. In other words, in line with what the Government wants. And what it wants is a vastly increased spread of those unlovely wind turbines across the landscape.

It’s not the Government’s fault, of course, that the windiest parts of Britain — the high, open moors of the West Country, North Yorkshire and the Scottish Highlands — also happen to be areas of outstanding natural beauty. But it’s surely disgraceful for ministers to stack the odds so heavily against environmental protesters and effectively to muzzle the democratic process.

Ed Miliband, the Energy and Climate Change Secretary, even suggests, chillingly, that it should be “socially unacceptable to be against wind turbines in your area” — and wrote to the Western Mail to tell the citizens of Devon and Cornwall that they will have “no option” but to accept more wind farms.

Naturally, the IPC is being touted as an even-handed body that will give protesters a (very limited) chance to make their case, and may even (if we’re lucky) hold some of its sessions in public. But John Healey, the Housing Minister, rather let the cat out of the bag when he said that ministers crave a “more efficient and predictable” planning system. Yes, I bet it will be predictable!

The irony is that this debate pits two green philosophies, both commendable, in opposition. One is the dash for renewable energy; the other is the fight to stop ugly developments swallowing even more green fields. But with the Government so gung-ho about wind farms, there’s no doubt in my mind about which way the battle will go — unless environmental and rural protection groups can quickly muster a lot of powerful voices to speak up for local democracy and accountability.

Yes, it’s true that the IPC will handle only big developments, so most already-existing wind farms wouldn’t have come under its remit. But the very fact that the new quango will be “more efficient and predictable” will probably encourage developers to make their schemes so big that they qualify for IPC handling, thus circumventing stroppy local authorities.

Already 50 such schemes are said to be waiting for IPC perusal, and the quango doesn’t even open its doors until next month. If you love feasting your eyes on the lush, unspoilt uplands of these isles, my advice is to get out and enjoy them while you can.

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