Doubts have been raised by a powerful Commons committee over whether ministers can meet a flagship pledge to release land with the capacity to build 160,000 homes by 2020.
The Public Accounts Committee (PAC) warned the pace at which Government real estate is being sold off needs to "accelerate significantly" if the end-of-decade target is to be met.
By the end of March 2016, almost a year into the initiative, departments had disposed of land with the capacity to build just 8,580 homes, or 5% of the target.
Performance across Whitehall ministries was patchy, with the Department for Communities and Local Government hitting 12% of its target by disposing of land with capacity for 4,326 dwellings, while the Transport Department reached only 0.2% of its target, disposing of land for just 71 homes.
Urging much greater transparency over how the initiative is being organised, PAC chairwoman Meg Hillier, said: "There is a desperate need for new homes and public land is an irreplaceable asset. Taxpayers clearly have a right to know whether they are getting a good deal from its sale and how many homes are being built as a result.
"Our committee laid bare some serious problems with the previous programme, not least that government had no coherent record of sale proceeds, nor did it record how many homes had been built or were under construction.
"I described the approach as 'wishful thinking dressed up as public policy' and in implementing the new programme it was vital the current Government learned from past mistakes.
"While we welcome measures taken by the Department for Communities and Local Government there is still much work to be done if it is to deliver on its promise to taxpayers by the end of this parliament.
"Sluggish sales have hindered progress towards the 2020 target while questions continue to hang over the potential of many sites earmarked for sale and whether homes will be in the places people want to live.
"Ultimately the public will judge the success of this programme on the basis of the homes built and the Government must make clear who taxpayers should hold to account for this."
Individual departments have been set their own target contributions, with the major contributors being the Ministry of Defence (land with capacity for 55,000 homes), the Department for Transport (38,000), the Department for Communities and Local Government (36,000), and the Department of Health (26,000).
The report states: "There is still a long way to go to ensure that departments release enough land, by 2020, with the capacity for at least 160,000 new homes.
"All departments have made a slow start in releasing land, and so the success of the programme will depend on accelerating land sales significantly in the remaining years to 2020.
"The slow start to the new programme also suggests that departments either took their eye off the ball at the end of the previous programme that ran up to 2015 or are struggling to find suitable sites; resulting in a stop-start approach when it was entirely foreseeable that the programme would be extended under the new Government."
The PAC report also expressed concern regarding the uncertainty over the potential for housing on many ear-marked sites as they are still being used to deliver public services.
A Department of Communities and Local Government spokesman said: "Previous governments hoarded swathes of public land, blocking vital housing sites from being built and costing taxpayers a fortune in upkeep costs.
"Since 2010, we acted quickly to free up public land to enable more than 100,000 homes to be built for hard working families and first time buyers.
"We are also taking direct action by using surplus public land and £2bn of investment to accelerate delivery of thousands of new homes during this Parliament."