The admissions loophole is revealed as new figures show that thousands of degree courses will accept students next year on the basis of AS-levels alone.
Key skills exams were central to A-level reforms introduced in 2000. They were meant to ensure that sixth-formers have reached minimum competence levels in the core subjects. About 90 per cent of schools offered key skills in 2001, according to the Secondary Heads Association.
The qualifications count on the university admissions tariff. Around 70 per cent of universities use the tariff instead of making offers linked to A-level grades. Level 2 key skills qualifications - the equivalent of a good pass at GCSE - are worth 10 points.
A key skill level 3 qualification - the level taken by most sixth-formers, is worth 20 points - equivalent to an AS-level grade E. If universities use the tariff but do not specify where the points come from, key skills qualifications could make up the bulk of the score.
Catherine Orange, chair of the Academic Registrars Council admissions group, said that if there was a shortfall in a student's grade, a key skills qualification could help them reach their point score. But universities have been warned not to take key skills points as a substitute for AS or A-levels.
Ms Orange said: "For institutions which have chosen to use the tariff there may be a need to limit the proportion of the total points which may be made up from key skills units."
In 2003, 4 per cent of the 27,000 degrees courses will be open to candidates with just AS grades, according to the Universities and Colleges Admissions Service.
A few universities offered places to students with just AS qualifications this summer. Tony Higgins, UCAS chief executive, said: "Departments within universities are becoming more flexible but they are developing entry profiles which indicate what is required to get on to a particular course. Key skills might be a part of it but not the substantive part."
A Department for Education and Skills spokesman said: "Universities are responsible for their own admission policies. Each course in each university has a different structure and demands a different range of skills and qualifications."