Affordable housing will double in a new development after intervention from the Mayor of London, though critics have named the development "inappropriate".

The Mayor of London, Sadiq Khan, called in a development to take place on the former National Institute for Medical Research site in Mill Hill after it was refused at the Barnet Council's planning committee, and has now approved the new development after doubling the level of affordable homes and including homes at social rent levels.

Mayor Khan also said he saved 119 trees which would have been felled and will plant 92 new trees.

However the Barnet Conservatives have branded the development "inappropriate" and said the reason it was originally refused was its size and its not being in-keeping with the area, along with the loss of trees.

The group also said his saving of trees has only happened due to his scrapping of 78 parking spaces, which some councillors fear would cause chaos.

Mayor Khan said: "Delivering more of the genuinely affordable homes Londoners need is one of my top priorities as Mayor and I will use all the tools at my disposable to do so.

"This development offers a significant number of high-quality homes which will be available through shared ownership, to help people struggling to buy a home on the open market.

"I have also been able to secure new homes at social rent levels within the development, which is key to helping Londoners on low incomes and to making sure we build a mixed community here."

The original application, which included 20 per cent affordable housing, has seen an increase to 40 per cent affordable, meaning 185 homes, including 131 for shared ownership and 54 at social rent levels.

Cllrs Val Duschinsky and John Hart, however,  say Mayor Khan "steamrolled" the plans for developers to consult new architects over the plans with his intervention,  which they believe to have been "cack-handed".

Cllr Dan Thomas, chairman of the assets, regeneration and growth committee, added: "Sadiq Khan has chosen to make Mill Hill residents’ lives hell in a desperate attempt to shore up his ridiculous campaign pledge to plant 2 million trees by 2020 — an impossible 1,370 a day."