Fears grow that universities will not give the courses parity of esteem with A-levels.
Universities could scupper the new work-related diplomas because they believe the courses are not hard enough, The TES has learnt.
The engineering diploma, one of five to be launched next year, will not be taken seriously by admissions tutors because it contains too little maths, an organisation representing 1,600 senior academics has said.
The TES understands that the construction and the built environment diploma and the information and communications technology diploma may be about to run into similar problems.
Leading universities have traditionally been sceptical about work-related courses and there appear to be few signs that this is changing. There is already speculation that admissions tutors at universities such as Oxford and Cambridge will not give the diplomas parity of esteem with A-levels and the International Baccalaureate.
Geoff Hayward, a member of the Nuffield Review of 14-19 education and an Oxford University lecturer, said: "I would suspect that there would be a group of universities that would be resistant to accepting the diplomas."
The diplomas have been billed as the most important education reforms going on anywhere in the world. Securing the support of higher education for them has been one of the Government's key aims.
However, engineering dons are furious at what they allege is downgrading of the maths content.
Students will only be required to receive 60 hours of maths tuition - less than an hour a week - for the level 3 engineering diploma, compared with about 360 hours for a maths A-level.
The Engineering Professors' Council, which represents 1,600 university professors and heads of department, has written to the House of Commons education and skills select committee to complain.
The council was involved in discussions last year in which it was agreed that students would spend 120 hours on maths and science. It believes the maths content in the engineering course has been cut in a "misguided" attempt to give it parity with other diploma courses.
The council also questions the assumption behind the diploma that enough teachers are available to teach work-related engineering skills.
In a letter to the MPs' committee, Professor Fred Maillardet, former president of the council, wrote: "The level 3 engineering diploma in its currently proposed form cannot be considered to be equivalent to A-level for the purposes of entrance to a university engineering course."
The council has been in discussion this week with those developing the diploma and a compromise may be reached that allows students to opt to study an extra 60 hours of maths. Details will be finalised by the autumn.
Graham Lane, chair of the Engineering Diploma Development Partnership, said that maths and science would be taught throughout the engineering diploma and that students could study an A-level in maths as part of their diploma programme.
This week the National Association of Head Teachers warned that the reforms were among several curriculum changes that could make 2008 a "meltdown" year in schools.