THE number of teachers in North schools is continuing to rise, new figures show.

But problems remain in recruiting to key posts such as maths, science and English, a union leader said last night.

The Department for Education and Skills (DfES) said that teacher numbers were at a 20-year high.

There were 419,600 full-time teachers in maintained schools in England in January last year, which was up by about 9,400 on the previous year.

Figures gathered from local education authorities in the North-East and North Yorkshire show that 25,094 teachers were in full-time posts at the start of the year.

Again, this was up, from 24,870 in January the previous year.

Last night, Terry Bladen, national senior vice-president with the NAS/UWT union, said the figures were welcomed, but "significant shortfalls" remained in some areas.

Mr Bladen, who teaches at Darlington's Eastbourne School, said: "Maths, science, English and the languages are still a problem.

"We are getting more people into teaching posts, but they are staying for shorter periods of between three and four years and then moving on, a decision which is usually due to their workload.

"There are also more people being recruited to teach outside their subject to fill spaces.

"So yes, there are more teachers, but the picture is blurred somewhat."

Nationally, the vacancy rate dropped from 1.4 per cent in 2001 to 1.2 per cent.

In January this year, there were 144 posts waiting to be filled in the North-East, down 30 on the previous year.

John Collings, assistant director of education at Hartlepool Borough Council, said: "We are recruiting some high-quality teachers, thanks to the excellent package of support for them we have available.

"But some local authorities are still facing difficulties and it is clear there is increasingly tough competition especially in subjects such as maths, in secondary schools."

The number of graduates applying to be trained as teachers up to June 21 had increased by 14 per cent on last year, the DfES said.

But the number of unqualified, trainee and foreign teachers working in English schools has continued to rise during the past five years, and now stands at 7,600.

Schools Standards Minister David Miliband said: "Finding and keeping good teachers remains a problem in certain areas, but we are continuing to make progress."