Teacher shortages in England remain a problem, with recruitment targets having been missed for four years, according to the National Audit Office (NAO).
Due to this, 28 per cent of of secondary school physics lessons are taught by teachers with no more than an A-level in the subject.
The NAO states that the government has a "weak understanding" of the extent of local teacher shortages.
"The department takes a national approach to recruitment but has more to do to understand important local and regional issues," the report says.
While the overall number of teachers has kept pace with rising pupil numbers, teacher shortages are growing, particularly in poorer areas and at secondary level.
More than half (54 per cent) of head teachers in schools with large proportions of disadvantaged pupils find attracting and keeping good teachers is "a major problem", compared with a third (33 per cent) of those in other schools.
In secondary schools, an increasing number of classes are being taught by teachers without a relevant post-A-level qualification in the subject. Across all secondary subjects, 14 out of 17 had unfilled training places this year, compared with just two subjects five years ago.
Head teachers' unions said the report echoed their own research.
"The acute difficulties of recruiting in maths, English, science and languages are now extending to most other areas of the curriculum," said Malcolm Trobe, interim general secretary of the Association of School and College Leaders.
Even with teacher shortages, the quality of education in England has been transformed by the most highly-qualified teaching workforce in history, resulting in 1.4 million more pupils being taught in good and outstanding schools compared with five years ago.
Posted by Tim Colman