A free school in north Devon has been put in special measures after inspectors rated it "inadequate".
Route 39 Academy at Higher Clovelly received the worst Ofsted rating in all four categories including "quality of teaching" and "pupils' outcomes".
The school opened in 2013 and has 131 pupils aged 11 to 18.
Route 39 has complained to Ofsted saying: "We strongly refute the judgement and the manner in which the inspection was handled."
Ofsted's report on its June visit said the school had not entered any pupils in Year 11 for exams and was "in breach of statutory requirements and the school's own funding agreement".
"Teaching has not prepared pupils in Year 11 well enough for the next stage of their education" and pupils' progress across Key Stage 3 was "inadequate", the report said.
Teachers' expectations of the quality of work were said to be "too low" and "exclusions are too high".
However the school "makes good use of its extended day to promote pupils' spiritual, moral, social and cultural development" and parents of pupils who have special educational needs "are very appreciative of the way the school cares for their children", the inspectors found.
Route 39 said on its website it had "addressed all safeguarding issues" and "employed an independent consultant to report on student attendance and exclusions".
It has also joined in a "management partnership" with South Dartmoor Multi Academy Trust "to ensure the academy is out of special measures within a year".
Free schools are independent of local authorities and paid for by central government.
There are now 500 free schools open or approved to open across England according to New Schools Network.