Almost two thirds (65%) had considered leaving their job in the past year, while more than half (54%) had considered leaving teaching entirely, the survey claims.
It found that teachers' top four concerns about their jobs were workload (chosen by 78%), followed by government changes to pensions (51%), pay (45%) and school inspections (41%).
Chris Keates, general secretary of the NASUWT, said three years of "relentless attacks" on teachers by the coalition government had resulted in a profession in crisis.
