Thousands of pupils may leave school with only a basic mathematics qualification, under proposals to overhaul England's secondary exams, subject experts fear.
Maths teachers say plans for a new diploma to replace A-levels and GCSEs could exacerbate the crisis which has faced maths in recent years.
The plans have also come under fire from English teachers unhappy at a requirement for all pupils to study "communication" rather than English literature or language.
With opposition from teachers of such important subjects, the diploma proposals of a Government task force led by Mike Tomlinson, the former chief inspector, could be in jeopardy.
Mr Tomlinson proposes that all teenagers should study a compulsory "core" of maths, communication and information and communications technology. He aimed to address employers' and universities' complaints that pupils currently leave school without mastering the basics.
The Tomlinson group expects most pupils also to take optional GCSE-type courses in English and maths at 16. Maths will continue to be a requirement at key stage 4.
At a Qualifications and Curriculum Authority conference last week, however, maths teachers given the chance to discuss the proposals were near unanimous in their opposition.
Doug French, of the Mathematical Association, said: "It's dangerous to separate the core from the rest of maths, because it could lead to more students dropping maths."
Mr Tomlinson said that without the proposed changes many pupils would continue to leave school without basic numeracy.