Sadiq Khan is on track to miss his affordable home building target, with just three months until the end of the financial year.
The Mayor said he would start between 17,000 and 23,000 affordable homes in 2019/20. But by December, just 12,546 were underway, putting City Hall on track for 16,728 homes by the end of March.
Mr Khan uses three definitions for “genuinely affordable” builds: shared ownership schemes to help private renters get onto the property ladder by buying part of their home; living rent, which cannot be more than a third of average incomes in the area; and even more heavily discounted social rent, the Mayor’s preferred option.
This contrasts with previous Mayor Boris Johnson, who defined “affordable” housing as 80 per cent of normal market rents.
Conservative London Assembly housing spokesman Andrew Boff said Mr Khan has presided over “missed targets and sluggish progress”.
Boff said: “The Mayor has failed time and time again to show any urgencyand recognise that housebuilding in London needs to be a sprint rather than a marathon.
He added: “Housing starts are of course important, but so are completions. We know that over the course of his term the Mayor has completed barely a third of the inadequate number of homes that he started.”
Just over 12,000 City Hall backed homes have been completed since Mr Khan took office in 2016, meaning almost two thirds of signed off projects are still unfinished.
But City Hall claims there are always more new starts towards the end of the year.
The Mayor met his house-building target last year despite having just 42 per cent underway by December, compared to 74 per cent underway this year.
And Mr Khan has improved his performance in the third quarter of the year. He started fewer than 5,000 homes in the first six months of 2019/20, but from October to December signed off 7,762.
On this basis the Mayor claimed he was “firmly on track” to reach 17,000 new starts.
He said: “Social housing plays a vital role in binding our city together and I’m proud that councils across London have bought into my vision and helped us deliver more genuinely affordable homes for Londoners than at any time since City Hall took responsibility for social housing.
“We can’t solve the housing crisis overnight, but this shows what we can do when Londoners work together. Now it is time for the Government to recognise what we have achieved, step up and give us the support and funds to keep building the homes London urgently needs.”