A “SECRET garden” will be lost for ever after plans for 143 luxury flats were approved by Islington Council on Monday.

Town hall planning chiefs agreed proposals to bulldoze the UK headquarters of children’s charity NCH – now Action for Children – in Highbury Park, Highbury, and build over a grassland area behind it.

Dozens of residents fought to save the 1.26 hectare site, which they said was home to many rare plants and is teeming with wildlife – but it will now disappear, along with four other historic buildings.

Islington Green Party spokeswoman Emma Dixon said: “The council has given the OK to build over a very rare piece of urban grassland that, according to the London Wildlife Trust, should be a site of importance for nature conservation.

“It’s just so sad this has been allowed to happen.”

A spokesman for Action for Children said: “We are very pleased that the committee granted planning permission. “This new development will including a large number of affordable homes, and open up this previously closed off private site to local residents.”