There are widespread concerns among industry leaders and exam boards about the introduction of Specialised Diplomas in England, experts say.
Some of the first courses will involve media studies
The chief of the Qualifications and Curriculum Authority said people felt there was a lack of clear management.
Similar concerns were reported as widespread by other members of the QCA board, minutes of its meeting show.
The Department for Education and Skills said it had made good progress in readying diplomas for launch next year.
"We're offering extra support to schools and colleges to help them prepare," a spokesman said.
The new Specialised Diplomas are being developed in 14 employment sectors and will combine theoretical and skills learning.
The first five are due to be available from 2008 in information technology, engineering, health and social care, construction and the built environment and "creative and media".
To offer them, schools have to go through an accreditation process or "gateway".
They are likely to need to collaborate with outside bodies such as local colleges or businesses to assemble the necessary resources and expertise.
The QCA's chief executive, Ken Boston, said the concerns had been raised with him in recent discussions with industry leaders and exam boards.
They also felt there was a need to ensure that all those involved knew what the other partners were doing, "and how the various pieces of activity will be brought together".
"These concerns were reported as being widespread by other members of the
board from their other sources," the minutes record.
Dr Boston was asked by the QCA's chairman to prepare a report outlining these concerns along with the current situation, challenges ahead and timetable of "critical milestones".
It is known that the diploma programme is flagged as "red risk" within the QCA - the highest of its four risk categories.
A source explained that this did not mean it was at high risk of going wrong - but that it was so complex and politically high profile that it would be disastrous if it did.
The Department for Education and Skills spokesperson said: "We're confident that the new Diplomas will be ready for September 2008.
"And it's our role to get behind schools and colleges that want to offer this exciting new opportunity, backed by industry, to their students."
The general secretary of the Association of School and College Leaders, John Dunford, said plenty of schools and colleges wanted to go ahead next year.
"I think it's important that 2008 has only a small number doing so, and that 2008 and 09 are treated as pilot years in which lessons will be learnt for the benefit of the vast majority of schools and colleges not taking part."
He added: "Schools and colleges are very worried about the sheer complexity and cost of starting a system with 14 diplomas running alongside GCSEs and other A-levels."
Head of education at the National Union of Teachers John Bangs said: "2008 is a cliff face. It's not only the diplomas that are going to hit schools there's the revised Key Stage 3 curriculum and new functional syllabi for maths and English GCSE.
"We have got a bunching of major reforms in secondary schools. We are constantly warning the DfES that we cannot do it all at the same time."
He also suggested the local authorities who are to deliver the new diplomas were not well prepared and had only one middle-ranking officer to deal with the whole thing.
Specialised diplomas were in the government's response to the Tomlinson report it commissioned on the future of 14 to 19 education in England.
Tomlinson had recommended overarching diplomas, taking in existing GCSE and A-level courses.
Ministers decided instead to keep those traditional qualifications, creating the impression that the new Specialised Diplomas were just another set of vocational courses for less academically-minded students.
Officials insist that is not the case and diplomas will give young people "a real alternative to traditional learning by offering an imaginative, high quality, innovative blend of general education and applied learning".
Those developing the creative and media diploma, for example, say it "will be academically robust in terms of both the breadth and depth of learning and the level of sophistication that will be required".
They add: "Critical thinking, analytical skills and effective communication skills are all fundamental...."