Where Rachel Reeves is about to give the Nimbys the biggest shock yet

Or in other words, “she has declared her willingness to fight battles against the Nimbys if necessary,” says John Myers, founder of the campaign group Yimby Alliance.

At a time when public finances are paralysed, planning reform offers a virtually cost-free route to growth. Regulatory reform does not require billions of pounds of investment or tax rises to fund it. The only cost to Labour will be political capital, of which Ms Reeves has plenty at the moment.

“It’s clearly part of their elected mission and they have a large majority. So they are in principle better placed to meet these challenges than any government since probably the period before the Second World War,” says Paul Cheshire, emeritus professor at the London School of Economics and a former government adviser.

The London commuter belt and the South East will be the scene of the biggest fights – and that’s where local Nimbys are likely to suffer the biggest jolts.

Under the current system, local authorities’ housing provision is assessed against their local targets. If local authorities deliver 85-95% of their target, they must increase their target by 5% over the next five years. If they deliver less than 85%, their target increase is 20%.

This system of sanctions became ineffective when the targets became advisory, but it should have new weight now that the targets will become mandatory again.

“They have put in place quite tough measures to enforce those targets. Over time that should mean it becomes increasingly difficult for local authorities to miss their targets,” Mr Cheshire says.

Labour plans to force local authorities that fail to meet their targets to accept development proposals. It could also go further and increase penalties for housing delivery tests or reduce the threshold at which they are imposed, says Simon Coop, senior director at Lichfield-based planning consultancy.

“Those who have consistently underperformed may be subject to additional measures.”

Nearly a third of local authorities will face some form of sanction when the targets become mandatory again because they have not consistently lived up to expectations, Mr Coop says.

“They are expected to increase their production rapidly and significantly.”