Ministers should abandon plans to reform the curriculum and qualifications and save time and money by allowing all state schools to adopt the International Baccalaureate (IB), according to a top public school head.
Anthony Seldon, master of Wellington College, believes the three programmes offered by IB for three to 19-year-olds inspire pupils through more active learning and reinvigorate teachers.
He says it is "puzzling" that most of the 150 or so UK schools offering the IB 16-18 diploma do not also offer the IB's 11-16 middle years programme (MYP), adopted by Wellington this year.
Dr Seldon is also a fan of the three-12 primary years programme and says all three have the potential to become a new "gold standard" in England. He told a conference of IB heads in Liverpool that "they provide us with the best hope of establishing a joined-up educational system, rather than the schizophrenic one we currently have".
"Every child would benefit from being educated in the primary years and middle years programmes," Dr Seldon added.
"These exist now, are tried and tested, and would save the coalition Government time and money if they were to stop exploring new alternatives with minimal shelf life."
The Government is planning to review the national curriculum and reform A-levels and has already encouraged state schools to consider alternatives to the GCSE such as the IGCSE.
But Dr Seldon told the heads that the MYP was "infinitely stronger and (more) flexible than either GCSE or that impostor of an alternative, the IGCSE".
Wellington allows its pupils to choose between the GCSE or MYP and IB Diploma or A-level. Dr Seldon told The TES this was because "I like the idea of choice".
Last month, Education Secretary Michael Gove said: "I am a great admirer of the existing International Baccalaureate and am determined to support a wider take-up. But the GCSE is a popular and resilient qualification, well understood by employers, teachers and students."
He proposed an "English Bac" for pupils achieving five good GCSEs, including "English, maths, a science, a modern or ancient language and a humanity".
But his proposal did not include an equivalent to the "personal project" that is compulsory in the MYP, which is also broader than his "Bac" suggestion, covering eight subjects.
The MYP, unlike the GCSE, can be adapted by schools to meet their own needs and uses moderated teacher assessment rather than external marking.
Dr Seldon said this was "core strength" and would prove an incentive rather than a burden to teachers.
"It gets teachers back in touch with why they joined the profession, which wasn't to be clerks delivering balkanised chunks of knowledge for examinations," he said. "Helping to design the curriculum of subjects they love is what enthuses teachers."
Asked whether ministers would back a qualification that relied on teacher assessment, Dr Seldon said they must learn to trust teachers and realise they were being de-professionalised by an over-centralised system.