Councils have given planning permission for more than 1.4 million homes since 2007 that have not been built, research has found.

A new report by the Institute for Public Policy Research (IPPR) says planned homes are often not built because developers instead want to increase the land’s value before selling it on, or they are ‘land banking’ to slow building rates and maintain high house prices.

The think-tank argued this meant the Government should not ‘rip up the red tape to get Britain building’, but must instead strengthen the planning system, which would also help restore nature, generate clean energy and build other important infrastructure.

It recommended exploring new laws to force developers to build within a certain time frame of securing planning permission or face sanctions.

The Government should also create a new Cabinet Office team to produce a national spatial strategy to oversee land use, the IPPR said.

Senior IPPR research fellow Dr Maya Singer Hobbs said: ‘Market driven house-building is broken, and won’t deliver the 1.5 million homes the Government has promised.

‘Years of deregulation and cuts to organisations like the Environment Agency means the planning system now operates as the last bastion of defence against bad design, nature degradation, pollution and over extraction of our waterways.

‘We must support local, regional and national planners to do their job.’

The Local Government Association’s housing spokesperson, Adam Hug, said: ‘Councils approve nine in 10 planning applications, but people cannot and do not live in planning permissions.

‘Councils must be given greater powers to ensure prompt build out of sites with planning permission.’