The government's flagship £45bn school building programme has been hit by delays, and risks being damaged by a lack of expertise, officials have said.
The DfES says it is getting plans back on track
The prime minister's delivery unit has stepped in to get the Building Schools for the Future project back on course.
The government pledged funds for the rebuilding of all England's secondary schools over 15 years from 2005-6.
But only three of the 17 local council areas in the first wave met their target to sign off proposals last year.
The Department for Education and Skills says that since then nearly all of these first 17 local authorities, which are some of the most deprived in the country, have had their plans agreed.
Sally Brooks, who manages schools capital for the Department for Education and Skills, told a Commons committee the programme had "slipped" from its "very ambitious timescale".
The project had been hit by issues to do with the "local authority funding process", she said.
"In fact the prime minister's delivery unit is, as we speak, doing an assessment of where we have got to on delivery of BSF so that we can take those lessons learned forward," she added.
She also said that targeting the Building Schools for the Future (BSF) programme on the most deprived and low-achieving areas of the country "was always going to be a very, very big task" because these are the local authorities under the most pressure.
She added: "The decision was made that that was the right place to start because of raising standards. Within that come extra challenges.
"The Treasury has acknowledged those extra challenges were there and we are working together on making sure that we learn the lessons going forward."
Lack of preparation
This was backed up by the chief executive of the body, Partnership for Schools, set up to assist schools and local authorities in setting up and managing their rebuilding projects.
Its chief executive Tim Byles said support needed to be more targeted to the specific needs of each local authority.
He added: "The very early projects, I am quite sure, did not have that degree of preparation."
Ms Brooks also acknowledged some fundamental difficulties with the way the project is designed to be managed by schools and local authorities - albeit with assistance from Partnership for Schools.
"It is a challenge because what we have at the moment are schools that are getting on with their day job who are not necessarily understanding how you can get involved."
Value for money
Concerns were also raised about the level of expertise in local authorities to manage such big projects.
Martin Lipson, programme director with public building project advisers 4Ps, said local authorities were finding it difficult to find experts and professionals in a "relatively limited market" to help them.
He added: "With lots of projects going on at the same time nationally, there is a limited pool of really good experts."
A spokesman for the DfES said Building Schools for the Future was a project of unprecedented scale.
"Such projects should not be taken lightly and while some slippage has occurred, this is because we want to ensure that the projects are of the best possible quality and offer the value for money that parents and pupils rightly expect.
"We are working closely with design experts such as CABE, Partnerships for Schools and Local Authorities in the areas where there has been slippage to ensure these are put back on track as soon as possible with most of the 17 local authorities in the first wave now either signed off or close to sign off.
"Future projects, such as those in wave four, have to demonstrate their readiness to deliver in order to be selected."