Communities Secretary Greg Clark is urging Whitehall departments to let go of surplus and redundant land and property for new homes.

Clark said departments should “loosen their grip” on sites that are standing idle so they can be released for new housebuilding, with a target to release enough land for 150,000 homes by 2020 – equivalent to the number of homes in Wakefield.

He said England’s 326 councils should also look at the “significant” land assets they hold, and use some of these plots, particularly those on brownfield sites, to provide new homes for their communities.

Clark said: “The chance to own your own home should be available to everyone who works hard and aspires to. That is what a government for working people is about – making sure people have the security they need to build a brighter future for them and their families.”

The new local government transparency code means councils must publish their property and asset registers.

Government accounts show that in 2011, councils held £223bn of assets – of which £108bn was in land and buildings.

The Housing Bill, announced in the Queen’s Speech, will require local authorities to establish and maintain a register of brownfield land suitable for housing development, which will include their own land.