Heritage campaigners want London Mayor Boris Johnson to go back to the drawing board rather than bulldoze an historic former children’s hospital to create what they say are poorly-designed new homes.

The Hackney Society, along with thousands of others who signed a petition, are against a plan to demolish all but the façade of Queen Elizabeth Hospital for Children, Hackney Road.

Objectors to the development on the border of Hackney and Tower Hamlets appealed to Mr Johnson to overturn the decision but in October he gave the go-ahead to replace the building – empty for 17 years – with 188 new homes.

David Shaw, of the Hackney Society, believes the scheme was rubber-stamped because of the Mayor’s target of 55,000 affordable homes by March 2015.

He said: “Right from the start we said we’d like to retain the building: they said it was impossible but they weren’t ever able to articulate why.

“On a local level we say it’s got some architectural merits, but overall it creates a really interesting bit of design in the social landscape – it’s a huge piece of social history in terms of the East End’s healthcare

“But throughout this process they’ve said, ‘This is it, take it or leave it, we’re not going to offer you anything else’.”

A report drawn up last year by one of the Greater London Authority’s senior designers said his team “remained unconvinced” by the arguments for demolishing all but the façade of the building, based on work carried out by their own heritage advisor Edmund Bird.

Mr Shaw warned: “If you look around we are getting very badly-designed buildings with a lifespan of 25 years – in this rush and haste to claim we are building for the future, we are losing the past. The question I’ve put to Eric Pickles [Secretary of State for Communities and Local Government] is when communities reject something with such force and at such a local level, why is it being ignored?

“The community voice should over-ride councils, or there should be a stop-gap to enable plans to be called in for review.

“The design is poor and the decision is going against the advice of heritage assessors. We’ve never seen anything saying it has to be demolished.

“Plus the affordable housing is only 38 per cent. The aspiration is 50 per cent, the minimum is 35 per cent – that should have been enough for it to be rejected.”

In a statement, Mr Johnson said the greatest priority facing London is its housing crisis.

“It is imperative that long- standing empty sites are put back into use to meet housing needs,” he said. “I’ve ensured the design incorporates some of the original architecture of the former hospital.”