Less than half of maths teachers in England's secondary schools have a degree in the subject, despite a national recruiting campaign to boost numbers.
A government-commissioned study of 327 secondary schools found that most teachers had a degree in the subjects they taught.
This tended to be more likely in the sciences, with 90% of these teachers having what was categorised as a relevant post A-level qualification.
In biology, for example, 85% of those teaching the subject had a relevant degree, as did 83% of those teaching chemistry and 72% of those teaching physics.
But the figures showed that only 47% of those teaching maths had a relevant degree, although 75% had a post A-level qualification of some sort.
One in four maths teachers did not hold any relevant post A-level qualifications, which include BEds, PGCEs and Certificates of Education.
And the percentage of lessons taught by maths specialists dropped from 88% in 2002 to 84% in 2007, according to the report, the Secondary School Curriculum and Staffing Survey 2007.
A spokeswoman for the Training and Development Agency (TDA) for Schools told the BBC News: "Fewer students are studying science, technology, engineering and maths subjects at A-level and degree level, meaning a smaller pool from which to draw in an increasingly competitive graduate labour market."
A government-commissioned study of 327 secondary schools found that most teachers had a degree in the subjects they taught.
This tended to be more likely in the sciences, with 90% of these teachers having what was categorised as a relevant post A-level qualification.
In biology, for example, 85% of those teaching the subject had a relevant degree, as did 83% of those teaching chemistry and 72% of those teaching physics.
But the figures showed that only 47% of those teaching maths had a relevant degree, although 75% had a post A-level qualification of some sort.
One in four maths teachers did not hold any relevant post A-level qualifications, which include BEds, PGCEs and Certificates of Education.
And the percentage of lessons taught by maths specialists dropped from 88% in 2002 to 84% in 2007, according to the report, the Secondary School Curriculum and Staffing Survey 2007.
A spokeswoman for the Training and Development Agency (TDA) for Schools told the BBC News: "Fewer students are studying science, technology, engineering and maths subjects at A-level and degree level, meaning a smaller pool from which to draw in an increasingly competitive graduate labour market."
