In a scathing letter, the UK’s secretary of state for housing has directed London Mayor Sadiq Khan not to publish his London Plan until he makes major changes to it.

“Housing delivery in London under your mayoralty has been deeply disappointing,” wrote Robert Jenrick, secretary of state for Housing, Communities and Local Government, criticising Khan’s housing delivery and targets outlined in the new plan.

Jenrick points out that the average delivery of 37,000 homes annually falls short of existing need and the target of 52,000 homes laid out in the mayor’s proposed London Plan.

“Clearly, the housing delivery shortfall you have overseen has led to worsening affordability for Londoners; and things are not improving, with housing starts falling a further 28% last year compared to the previous,” Jenrick wrote.

Planning consents increased by 42% between 2015 and 2018. Yet it is not enough to keep pace with demand.

Jenrick directs changes in the forthcoming London Plan, including making use of vacant industrial land, consider building in London’s Green Belt “very special circumstances,” and promote higher density developments “in areas that are well connected to jobs, services, infrastructure and amenities by public transport, walking and cycling.”

Khan will now have to produce a revised London Plan taking in 11 sections of changes Jenrick lays out before it will be approved.

“Robert Jenrick is showing he means business, just a day after he told developers they need to be building higher, and over key transport links, which is what we’ve said all along,” said Andrew Southern, chairman of property developer Southern Grove, in response to the letter.

“What the industry, and Londoners, want now though is for politicians in central and devolved government singing from the same hymn sheet,” Southern notes. “The housing crisis is too big a problem not to be a cross-party issue.”