There are warnings of a shortfall in maths teachers
The shortage of qualified maths teachers in England and Wales is to worsen, a survey suggests.
Analysis of advertised teacher vacancies and numbers of trained teachers suggests there will be a shortfall in the next academic year.
Professor John Howson says the overall picture is one of a north-south divide, with the south struggling the most.
The Training and Development Agency for Schools says overall, the proportion of trainee teachers accepted is on target.
Professor Howson, from Education Data Surveys, said only about 2,000 maths teachers were likely to be trained this year, with even fewer next year.
But secondary schools across England and Wales have advertised 1,650 vacancies for maths teachers already this year.
This represented about 75% of the likely total number of maths trainees qualifying this year.
With a proportion of those expected to drop out or go to private schools, Professor Howson says the shortage will get worse.
The government has been working to increase the numbers of people training to be maths teachers, with offers of "golden hellos".
Professor Howson said: "Once again the government's failure to recruit enough trainee maths teachers means that some schools will be short of properly qualified maths teachers.
"Parents should ask what the government is doing about this issue. "What is even more alarming is that recruitment to training courses for 2008 is falling behind the levels seen last year."
The research looked at the regional breakdown of advertised vacancies.
The findings suggest teacher shortages are most severe in London and the south east of England.
In London, 603 "main scale" vacancies were advertised in April, compared with 513 advertised in April 2007.
Figures for south east England were 635 compared to 444 last year and for the north east of England were 124 against 81 last year.
In Wales, fewer vacancies were advertised this April compared to last (43 against 118). The situation in the north west of England also appears to be improving, with 360 vacancies advertised this April and 468 in April 2007.
The Training and Development Agency for Schools (TDA), which is charged by the government to oversee teacher recruitment, says overall, the proportion of applicants being accepted on to teacher training courses is on target.
The organisation's chief executive Graham Holley said: "TDA figures from last year showed the number of trainee maths teachers had reached more than 2,300 for the first time.
"We are working hard to attract people with an interest in maths to the teaching profession, in what has become an increasingly competitive graduate labour market.
"We have a range of incentives to increase the supply of teachers offering maths, such as enhancement courses for existing teachers of other subjects to bring their maths skills up to date, returners courses, and higher bursaries (£9,000) and golden hellos (£5,000)."