Almost a quarter (23 per cent) of teachers are considering quitting teaching, compared with just 17 per cent last year, new research finds.
The report from the National Foundation for Educational Research (NFER), partly based on a poll of more than 2,000 teachers in England, identifies workload as key reason for the increase.
The news comes as Teach First has revealed radical changes to its teacher-training programme. It aims to cut workload, increase support and reduce the number of dropouts by spreading the assessments for trainees over two years instead of one.
Currently, one in 10 Teach First participants drop out of the programme before the end, despite the risk of dropouts having to pay back up to £4,000 to cover some training costs.
Unions argue that the pace of policy reform during the academic year 2015-16 has played a major role in the increase in teachers seeking to leave by adding to an already significant workload.
The NFER, which carried out a series of surveys and interviews with teachers between June 2015 to May this year, suggests keeping staff engaged can help to improve retention rates despite the pressures.
Job satisfaction, having adequate resources, reward and recognition, and being well supported by management were among the factors associated with successful retention in the research.
The new report, Engaging Teachers: NFER analysis of teacher retention, reveals a strong relationship between teachers' engagement and their desire to leave. It finds that 90 per cent of engaged teachers have no plans to leave, compared with just 26 per cent of disengaged teachers.
Maths teachers and senior leaders are less likely to consider leaving and are also more highly engaged, the report finds. But science teachers and experienced male teachers are significantly more likely to consider leaving, even after accounting for their relatively high level of engagement.
The Department for Education said it recognised the "challenges" facing teachers and was working to address their concerns over workload and pupil behaviour.
This is an edited version of two articles from the 9 September edition of TES. Subscribers can view the full NFER story here and the Teach First story here. To subscribe, click here. This week's TES magazine is available in all good newsagents. To download the digital edition, Android users can click here and iOS users can click here