Taxpayers must be told if the Government is securing value for money under its programme to sell public land for house-building, an influential committee of MPs has concluded.
The Department for Communities and Local Government (DCLG) chose not to collect "basic" information on how many homes had been built or the amount of cash raised by sales, the Public Accounts Committee (PAC) said.
Meg Hillier, the Labour MP who chairs the PAC, added it was an "insult to taxpayers" that potential economic benefits of the land sales had been put at risk by "such short-sighted Government mismanagement".
The PAC added its criticism of the scheme, which initially aimed to free up enough land for 100,000 properties to help ease the housing shortage, after the National Audit Office raised concerns in June.
Ministers have made a further pledge to release by 2020 enough land with the capacity to allow a further 150,000 houses to be built.
But the PAC has called for DCLG and the Homes and Communities Agency to better assess if the scheme offers value for money as it seeks to hit the new target, adding: "Taxpayers deserve to know how many homes have actually been built."
DCLG said the previous coalition administration sold off enough land for an estimated 109,950 homes by the end of March 2015, which included 15,740 on land disposed of before the 100,000 target was set.
The department also said it had been asked to ensure the land was released rather than also focus on housebuilding, adding it had a "robust" system to check how many properties the land could provide for.
On employment, the PAC said DCLG could not be specific on how many jobs had been created by the programme despite suggesting it would support 25,000 by 2015 and an estimated 200,000 for the house-building.
The MPs recommended the department to collect and audit data to ensure the potential new jobs were created.
The committee's report stated: "With much greater ambitions for land disposals in the new Parliament, the department must address the weaknesses in the current programme, and the department has accepted that it needs to improve its general monitoring.
"If it is to oversee the new programme effectively then this must specifically include tracking sale proceeds and progress with the actual construction of new homes, and overseeing the programme in a way that gives Parliament and the taxpayer much greater assurance over the value for money achieved from all disposals."
The report added DCLG had said it had begun to check house building on certain sites since the NAO report was published.
Ms Hillier accused the Government of showing an "alarming complacency" over the disposal of land as she warned there was "no means of knowing" whether taxpayers had secured a good deal or not.
She also said: "It is an insult to taxpayers that the potential economic benefits arising from the sale of public land should be put at risk by such short-sighted Government mismanagement.
"With the next housing target already announced, the Government needs to learn from its mistakes."
A DCLG spokesman said: "Previous governments allowed valuable brownfield land to go unused whilst housebuilding levels crashed to their lowest levels since the 1920s.
"We have got the country building again and are releasing surplus Government land to protect taxpayers from paying for their upkeep and build the homes families need.
"This has released enough land to build 109,000 new homes and we now want to go further and faster with land sales for a further 150,000 homes by 2020, helping people achieve their dream of home-ownership."