Every Whitehall department holding significant land banks will this autumn publish plans to release the land.

Property specialists are to assist the Public Expenditure Committee, chaired by Cabinet minister Francis Maude, in chasing up the departments to ensure all surplus land is made available.

Local authorities across the country are also being urged to follow suit. Later this year a map  and national register will be launched to show land and buildings owned by public bodies in each area.

Shapps has singled out several Homes and Communities Agency  sites which will be sold off immediately including the 40ha Fairmile site in Oxfordshire, which will become a 350-home development and pilot for the Government’s build now, pay later scheme.

Other sites earmarked include New Covent Garden Market in Vauxhall, south London, which is scheduled for 2,300 apartments.

Shapps also released three MoD sites in Bath  – Foxhill, Warminster Road and Ensleigh –  which are earmarked for 1,200 new homes over coming years.

Shapps said: “The work starts today, with sites already being brought forward by three different departments, including my own, some of which will be available on new terms so developers can start building straight away.

“So we are already off to a flying start – it is now for developers to come forward, make the most of this unique opportunity, and help contribute to our country-wide efforts to help get the homes this country needs built.”

Mark Clare, Chief Executive of Barratt Developments PLC, said: “This is a big step in the right direction. The rapid release of publicly owned land has the potential to be an effective catalyst for increasing the supply of land for new homes in this country during the next few years.

“Barratt has an established track record of working with public sector partners to build out important sites and deliver desperately needed new homes. We are already working on a number of Build Now Pay Later sites with the public sector and, in the wake of today’s announcement, will be looking at ways to expand and deepen that partnership.”