The governors of a Radlett new free school set to open in September say they feel "badly let down" by the Department of Education after it failed to secure a site in time.
Harperbury Free School has announced it has been forced to delay its opening until September 2015, disappointing 194 families who applied for a place for their children for this academic year.
The school was set to be built on land at the Harperbury Hospital site off Harper Lane in Radlett, but the Department of Education has not yet finished negotiations with the Department of Health, which owns the land.
The news came after head of governors Clive Glover wrote to schools minister Lord Nash expressing his concern about the time it has taken to secure a site.
In response, the minister said he had instructed his department to carry out a full feasibility study into building the school at the former Harperbury Hospital site, looking at costs and other issues.
Mr Glover expressed "amazement" the feasibility study had not yet been completed, but welcomed the fact that progress was finally being made.
The postponement was one of three options identified by the minister, which included cancelling the project completely or building the school on an industrial estate.
The school was not told whether the land, sandwiched between a busy road, a railway line and an access road shared with heavy goods vehicles, would be safe for students or staff, meaning it had to decline the offer.
Intended to provide a "rigorous and holistic" education for children in Radlett, St Albans, Bricket Wood, Borehamwood and Shenley, the school had already recruited its first intake of Year 7 pupils.
Mr Glover said the option of deferment, while unwelcome, was the "only realistic option".
He added: "We are acutely aware of the disappointment this will cause to the hundreds of families who have supported us over the past few years and, in particular, the 194 families who have applied for places for their children starting this September.
"Unfortunately the securing of a site is the one part of the free school process that is out of the hands of the proposer groups and firmly in the hands of the Department for Education's Education Funding Agency (EFA) and they have badly let us and our parents down."
Mr Glover said he was grateful for the continuing support of many local parents, residents, local organisations and businesses as well as that of the local MPs, Anne Main and James Clappison.
He added: "We are determined to push on with our vision for Harperbury Free School and will continue working closely with the DfE and EFA to ensure that we can now open in September 2015."