The Government is poised to reject the most radical aspects of this week's Tomlinson report, which proposes the biggest reforms of secondary education for more than half a century.
Within days of being presented with the blueprint for a new, all-embracing diploma, ministers appeared to be having doubts about the plans, putting themselves in conflict with much of the education world.
The dispute centres on changes to the GCSE which would mean that most youngsters would take few external exams until age 18.
Ministers are extremely nervous about the bigger role for teacher assessment in the new diploma system, which would be implemented by 2014.
The Prime Minister said that the diploma would not replace GCSEs and A-levels, while David Miliband, school standards minister, said the titles of current qualifications would be retained.
Charles Clarke, the Education Secretary, said that any new system would be based on traditional, externally-assessed exams, though the report suggests teacher assessment would dominate.
But David Bell, the chief inspector, said earlier in the week: "The change in mindsets that (the report) calls for will not come about if people retreat to the bunkers in an attempt to defend GCSEs and A-levels."
The 207-page report by Mike Tomlinson, the former chief inspector, recommends a four-level diploma, embracing all secondary qualifications, in which pupils would be assessed mainly by teachers until advanced level.
Vocational qualifications would be improved and absorbed in the new structure, with all pupils having to pass courses in basic literacy, numeracy and computer skills and more demanding courses provided for the most able.
Members of the inquiry group see teacher assessment as crucial. Yet Mr Clarke did not refer to it in a lengthy Commons debate on the proposals.
Ministers will not respond in full until they publish a White Paper next year.
John Dunford, general secretary of the Secondary Heads Association, said ministers' reluctance to back teacher assessment "demonstrates a major lack of confidence in the teaching profession".
The chances of the reforms being implemented in full have also been undermined by the Conservatives' refusal to back a system based on teacher assessment. Ministers say they need consensus to go forward with changes.
Michael Howard, the Tory leader, also pledged to retain the GCSE and A-level titles under any new diploma and promised a return to the system in which fixed proportions of students achieve A grades at A-level.
The Government risks a confrontation with much of the education world if it vetoes the teacher assessment plan. Organisations ranging from England's General Teaching Council to universities, private schools and headteachers'
leaders have backed the move.
News 6, Leader 22