Humanists are up in arms this week after England's new qualifications regulator barred an exam board from making humanism central to its religious studies GCSE.
The British Humanist Association - which has launched legal action against the decision - described Ofqual's ruling as a "kick in the teeth" to those who had worked hard towards making religious studies more inclusive.
It all looked so different back in April, when the OCR exam board published a draft syllabus that would have been the first to allow pupils to study humanism alongside six major religions. No other board has done so.
The course, due to start next year, would have examined pupils on the perspectives that different belief systems bring to issues such as euthanasia and abortion.
Other topics included the nature of good and evil, medical ethics, and death and the afterlife. Humanists greeted the new syllabus with delight.
But their joy was short-lived. Ofqual, which has to approve draft syllabuses, has ruled against making the study of humanism a central part of the GCSE, stating that it is not a religion but a "body of belief", and should not, therefore, be given equal weighting.
An Ofqual spokeswoman said: "The subject criteria for the GCSE in religious studies require the study of one or more religions.
"These criteria were created by experts following extensive consultation. Non-religious philosophies such as humanism may also be studied, but not to the total exclusion of religion."
Ofqual said that its problem with OCR's original draft GCSE was that it would have been possible for pupils to study only humanism, rather than any religion, in all four modules of the new GCSE.
OCR was working this week on adapting the course, but humanism will not form a major part.
Approving new GCSEs was one of the first major tasks for Ofqual, which took over the regulatory functions of the Qualifications and Curriculum Authority in April.
The humanists were so enraged by the Ofqual ruling that their association has lodged papers with the Administrative Court in central London and is seeking a judicial review of the decision. It is also considering challenging the ruling under human rights legislation, on the grounds that pupils with humanist beliefs should not be discriminated against.
Andrew Copson, the association's director of education, said: "The stance of Ofqual will be a great disappointment to the many teachers, parents and pupils who were as pleased as we were when OCR included the option of humanism in their GCSE.
"We have issued legal proceedings against the decision, as we believe that it is unlawful. It threatens to turn back the progress of recent decades - towards a more inclusive, educationally valid and objective study of RE - and is a real kick in the teeth for all who have worked for that progress."
The association can also be expected to mobilise its small army of celebrity supporters behind the cause. Among them is AC Grayling, the high-profile philosopher, who said: "If schools are teaching about religious views, they must also teach humanist ones."
An OCR spokesman said that the board was disappointed too: "We are sorry to see humanism reduced, as we felt it added an extra dimension that would have been welcomed by many learners.
Feedback from schools and colleges highlighted the popularity of humanism, while both the Government and the QCA have previously recommended that religious studies should include it.
"Although we accept that humanism is a body of belief and not a religion in the strictest sense, we hope the option to study humanism as part of religious studies GCSE is something that the QCA will consider including in the near future."