BASIC English, maths and computer skills are being neglected by sixth-formers because universities have not included the qualifications in their entry requirements.
As well as studying up to five AS-levels in the first year of A-levels, students also complete portfolios and sit exams in what are called key skills.
But six months into the first year of the communication, number and information technology qualifications, pupils have realised that they will not lose out on a university place if they neglect them.
John Dunford, general secretary of the Secondary Heads Association, said already overworked teenagers have been forced to prioritise. "Students are putting in 60 hours a week to keep up with four or five A-level subjects. Some have dropped subjects and reverted to the traditional three areas of study. And some have put the key skills element on the back-burner. There needs to be a strong indication that universities value them."
While the new Universities and Colleges Admissions Service tariff gives key skils up to 30 entry points, many places will be conditional on a combination of achievement at AS and predicted grades at A2.
John Hopkins, head of Gwernyfed high school, Powys, said universities, such as Leeds, were putting out the message that it was neither an advantage nor a disadvantage to have key skills.
"The top 50 universities are fairly non-committal. Given that the workload this year has increased by a third for some students, there must be a compelling reason to do key skills and students are not convinced there is one."
Key skills are not compulsory but the Government has made it clear that they should be taught. A Secondary Heads Association survey to be published shortly found nearly 90 per cent of schools offered them.
Tony Higgins, UCAS's chief executive, said many universities were not asking for key skills but probably would make them an entry requirement within a few years.
Leeds University said it would not make key skills mandatory until all students had the chance to take them.