A flagship education programme set up by former Education Secretary Michael Gove is in disarray after revelations that costs were more than ten times over estimate.
The programme encouraged parents and independent groups to set up their own schools - called free schools - to be funded by the Government.
A report by the National Audit Office (NAO), published on Wednesday, said that by March 2015 the Tories had spent £1.8 bn opening 305 free schools.
In 2010 the Department of Education (DfE) estimated opening 315 schools would cost £900 million.
Labour MP Angela Rayner accused the Tories of wasting millions “opening free schools in areas that do not need them”.
Free schools, Gove’s brainchild, were much talked about in the run-up to the general election in May 2010.
In their 2015 manifesto the Tories promised to build 500 more free schools by 2020.
But the NAO said the DfE expected the programme to cost a total of £9.7 billion by March 2021.
It found the Government had spent more than £30m on just four plots of land for free schools.
The report also said that crumbling school properties posed a “significant risk” and repairs would cost £6.7 billion.
Liberal Democrat education spokesperson John Pugh called the report “a devastating indictment of government financial mismanagement.”
“While many existing schools are struggling day-to-day in the face of harsh budget cuts, and many are unable to afford basic repairs and maintenance, it is disgraceful that money is being used so carelessly elsewhere,” he said.
A DfE spokesperson said: “As the NAO acknowledges, we have made more school places available, and in the best schools.”
“The free school programme is a vital part of this – more than three quarters of free schools have been approved in areas where there is already demand for new places and the vast majority of those inspected are rated good or outstanding by Ofsted.
“The Government is making a huge investment in the school estate of £23 billion up to 2021, to create a further 600,000 new school places, deliver 500 new free schools, and rebuild and refurbish buildings at over 500 schools.
“But we want to go further. That’s why we have set out plans to create more good school places, in more parts of the country, by scrapping the ban on new grammar schools, as well as harnessing the expertise and resources of our universities, and our independent and faith schools.”