A row broke out between Sadiq Khan and the Government on Tuesday as ministers threatened to strip the mayor of his planning powers if he does not agree to a review of house building in London.
Housing Secretary Michael Gove accused the Labour mayor of being too focused on building affordable homes in the capital, which meant a number of new developments were not going ahead.
But Mr Khan hit back blaming Tory ministers for "regularly intervening to block new building in London", and City Hall produced figures suggesting construction in the city outstripped the national average.
"Since I’ve been Mayor, London has out built the rest of the country, with more new homes of all types, including more new council homes being built than at any time since the 1970s," the Mayor said.
Mr Gove has tasked a panel of housing, council and legal experts to review the London Plan, which sets out how the city should be developed, and find where building in the capital can be sped up.
During a speech at the Royal Institute of British Architects, he said councils that “delay or deny” legitimate housebuilding will be stripped of powers.
He singled out London as one of the key areas the Government would be targeting.
"Radical action is required in London, where the homes we need are simply not being built," he said.
"In the last three years the average number of net additional dwellings provided by the Mayor has been just 38,000. That is 15,000 fewer homes every year than the Mayor’s own target in his London Plan....
"London has the lowest level of home ownership in the country....We are pumping billions of pounds of central Government money into building affordable homes in London but the Mayor’s approach is frustrating delivery.
"I am strongly in favour of affordable housing. But his requirement for such a high percentage of affordable homes in every new development imposes such significant costs that development does not go ahead – and so we get no new homes – and no new affordable homes."
Christopher Katkowski KC, Bedfordshire Tory councillor James Jamieson, architect Paul Monaghan and town planner Dr Wei Yang will review the London Plan, and "identify where changes to policy could speed up the delivery of much needed homes in urban city sites the heart of our Capital", Mr Gove added. They will report their findings to the Department for Levelling Up, Housing and Communities early next year.
"I hope we can agree a plan for reform and delivery with the Mayor," Mr Gove said.
“But if not, I reserve the right to intervene. If housing targets are to mean anything we cannot have failure to meet them in such a terrible way persist under Labour’s London Mayor."
City Hall argued that new analysis has revealed a gulf in the rate of housebuilding between London and the rest of England.
Since Mr Khan was elected in 2016, London’s devolved planning framework has achieved a rate of housing completions that’s 20 per cent higher than the rest of the country, a spokesman for the Mayor said.
In that time 116,000 low-cost council and housing association homes have been built or are under construction in London.
Mr Khan said: “Thirteen years of failure on housing by the Tory government has meant big cuts in investment and a go-slow on homebuilding nationally. But it’s a different story in London.
"The progress we are making in London is despite NIMBY Tory Ministers regularly intervening to block new building in the capital. Just imagine what we could achieve with a Labour Mayor and a Labour government working together.
“It’s clear the Tory candidate for Mayor would deliver more of the same failure on housing. The Tories have failed the country, we can't let them fail London too.
“Labour is the party of building, and as Mayor of London, I’m determined to deliver the homes Londoners need so that we can continue building a better, fairer London for everyone.”
