Unions were this week completing their responses to the Green Paper on secondary education.
Most praised the general aims behind the proposals but found crucial faults with the details, particularly with the plans for an overarching matriculation diploma.
The National Union of Teachers is among the organisations concerned that diploma awards are proposed for pupils at the intermediate and advanced level, but not for the foundation stage. To qualify for the intermediate diploma, students will need at least five A*-C grade GCSEs or equivalent.
The union warned this omission would exclude approximately half of the young people in England from achieving the diploma and undermine their confidence.
This fear is shared by the National Association of School Masters Union of Women Teachers and the independent schools' Headmasters' and Headmistresses' Conference. Both said the lack of a foundation diploma was illogical and "damaging to those for whom it would represent significant achievement".
Plans for a distinction A grade at A-level were also widely panned. The NUT warned that this would place an unnecessary burden on students and discourage them from higher education.
The Green Paper's emphasis on vocational courses was welcomed, although some were concerned that they would still be perceived as subjects for lower-achievers.
The HMC said: "It is difficult to imagine a time when students will be told they cannot cope with leisure and tourism and must lower their sights to physics and Latin."
But the Association of Teachers and Lecturers suggested that the vocational courses could be given greater status if all students were required to pick at least one from an options menu. The ATL's response to the Green Paper is the most radical, calling for a 10-year programme of reform and the introduction of a baccalaureate-style qualification.
Other unions were unconvinced about a baccalaureate, but agreed that the Green Paper had failed to go far enough to encourage pupils to take a wide range of courses and expressed disappointment at the sidelining of languages.
Sue Kirkham, chair of the Secondary Heads Association curriculum committee, said she was disappointed that no safeguards were planned to ensure that students predominantly studying humanities subjects took a science subject and vice versa.
She added that the Green Paper proposals had missed a prime opportunity to recommend greater internal assessment, which would cut pressures on teachers and students. Mrs Kirkham, who is headteacher of Walton secondary in Stafford, said: "My school has been an exam factory this month, but there is nothing in the Green Paper to deal with that situation."
The consultation deadline is next Friday.