Nearly one in 100 full-time teaching posts in England were either vacant or filled temporarily in 2014, BBC reported based on Department for Education figures
There were 1,030 vacancies last November, up a third on 2013, the highest number since 2010, when the DfE started compiling figures in November.
Meanwhile, teachers on contracts of between one and three terms filled 3,210 posts, up nearly 38% on 2013.
Teacher numbers, at 454,900, up more than 5,000, were at an all-time high.
The proportion of English, maths and science teachers with a relevant post-A-Level qualification dropped slightly over the same period: in maths, from 77.6% to 75.8%; in English, from 79.9% to 79.4%; in science, from 85.7% to 84.9%
Shadow Education Secretary Tristram Hunt said ministers were set to miss recruitment targets for a fourth consecutive year, including in crucial subject areas such as maths and physics.
“This is a very worrying trend that means more children are likely to be taught science by those trained to be PE teachers, and more and more teaching assistants stepping in as teachers,” he said.
“Parents expect better and pupils deserve better.”
Schools Minister Nick Gibb said: “Recruitment is a challenge as the economy improves and competition for new graduates intensifies, which is why we are focused on attracting more top graduates into the profession, particularly in the core academic subjects that help children reach their potential.
“Our recruitment campaign, Your Future Their Future, is working, with registrations to our Get Into Teaching website up by almost 30% compared with last year.
“We continue to offer bursaries of up to £25,000 as well as scholarships in priority subjects such as physics and maths.
“We are driving forward our £67m package to transform science, technology, engineering and maths teaching and recruit up to 2,500 additional maths and physics teachers.”
Education workforce expert John Howson warned the situation was likely to get worse in the near future.
Based on official predictions of how many teachers would be needed, only 93% of primary and 91% of secondary teacher-training courses had been filled last year, he said.