English primary schools lost 800 teachers last year as falling pupil numbers began to bite, Government statistics show.
While overall teacher numbers have increased, the picture is reversed at key stage 1. Class sizes for five to seven-year-olds have risen, with thousands more infants being taught in groups of more than 30.
Critics argue that the Department for Education and Skills should take advantage of the falling rolls to reduce primary class sizes.
But with around 50,000 fewer primary and nursery pupils, DfES officials say teacher cuts in the sector could have been a lot worse, with a potential loss of up to 2,000 posts.
The overall teaching force in the English state system increased by 4,200 to 427,800, the highest since 1981, according to the figures collected in January. Primary and nursery school teacher numbers are down to 196,700, but secondary teachers rose by 4,300 to 211,100 and those in special schools, pupil referral units and education elsewhere by 700 to 20,000.
Charles Clarke, the Education Secretary, said the figures demonstrated the success of his department's attempts to limit the damage done by last year's school funding crisis.
They categorically proved that media surveys last summer predicting mass redundancies were wrong, he said. But the statistics give net totals of teacher numbers and do not show whether there have been redundancies.
They also reveal that only 1,800 of the extra 4,200 staff are qualified teachers. Another 1,800 training on the job and the remaining 600 extra are either teachers trained overseas or instructors without qualified teacher status. The vacancy rate fell to 0.7 per cent compared to 0.9 in 2003 and 1.2 in 2002. London remained hardest hit with 680 recorded vacancies, but no region saw an increase.
There were more vacancies across the country recorded for maths teachers than any other subject, at 270, followed by science teachers at 240.
Mr Clarke said that increasing teacher numbers, alongside a 16,300 rise in the number of support staff to 241,700, nailed the "lie" that the school workforce agreement was about replacing teachers.
But the primary pupil-teacher ratio worsened slightly to 22.7, from 22.6 in 2003; while the primary pupil-adult ratio improved from 14.3 last year to 14. If the trend continued it could support claims from workforce agreement critics who say it is really to replace teachers with support staff. But Mr Clarke said his department was working to ensure that both ratios improved in future.
The overall nursery, primary and secondary pupil-teacher ratio improved slightly from 17.9 in 2003 to 17.7. The average primary class size fell from 26.3 to 26.2 pupils and secondary from 21.9 to 21.8. But more than 23,000 infants are being taught in classes larger than the statutory 30-pupil limit. That represented an extra 5,754 KS1 and reception pupils in such groups compared with last year.
Chris Davis, chairman of the National Primary Heads Association, was concerned about the loss of so many primary teachers.
The head of Queniborough primary school in Leicester said: "I hope this will be an opportunity to decrease class sizes rather than to close schools, which is the other obvious alternative.
"There will be pressure from councils to close smaller schools when what we should be doing is increasing per-pupil spending to retain teachers so that the next generation gets the best start in life."