Burnt out teachers urgently need better working hours and more support to stop them leaving the profession, the Liberal Democrats say, as the new term approaches.
Nearly half of the teachers surveyed by the party in England said they were planning to quit the classroom in the next five years, with many saying they felt overworked and stressed.
The Lib Dems are urging new Education Secretary Lucy Powell to fully fund teachers' pay, rather than raiding school budgets to cover increases, and to bring in limits on overtime.
The Department for Education said last year saw the lowest rate of teachers leaving the profession since 2010 but acknowledged there was "more to do".
The survey asked more than 900 teachers, headteachers and Special Educational Needs Coordinators (SENCOs) across England how long they planned to stay in teaching.
Almost half of those in post said they were considering leaving teaching in the next five years, while one in ten were planning to spend less than a year in the job.
More than three quarters of those surveyed, which included former teachers, said they had felt "frequently or constantly burnt out" while at work.
Respondents cited high workloads on marking, lesson preparation and other tasks, which they said gave them less time in the classroom.
The Liberal Democrats' schools spokesperson Caroline Voaden said this pointed to a government that is "not listening" to the profession.
"We rely on teachers to educate our children, the least we can do is make sure they want to come back after the summer," she said.
Teacher retention is a challenge successive governments have had to grapple with.
The National Education Union (NEU) reported that 4 in 10 teachers were planning to quit over "huge workloads and excessive accountability" in 2019.
This latest survey was also conducted with the help of the NEU, as well as the Association of School and College Leaders (ASCL).
"After over a decade of austerity and chronic underfunding in our schools the system is on its knees" said the NEU's general secretary Daniel Kebede.
"The new academic year is the perfect time for Andy Burnham to signal a fresh start for our schools" he added.
"That means fully funding the pay award and properly funding all our schools and colleges to stem the recruitment and retention crisis and give children the education they deserve."
"As Lucy Powell enters her first term as education secretary the Liberal Democrats are calling for her first act to be to introduce an emergency package of 'back to school' measures to face this crisis head on," Voaden said.
The Lib Dem proposals include the government fully funding teacher's pay, which will increase in England by 3.5% from September, with an additional 3% the year after.
Currently, half of the pay increase will come from existing school budgets.
The party is also calling for proper enforcement of teacher's legally mandated working hours, the introduction of reasonable limits on overtime, and for all schools to be required to introduce flexible working policies.
The party did not identify where funding might come from to pay for the policies.
An education department spokesperson said: "We know teachers do an incredible job and we're determined to make sure that dedication is matched with the right support.
"Last year saw one of the lowest rates of teachers leaving the profession since 2010, and a record number of teachers returning to the classroom, but we know there's more to do.
"We're taking action by announcing pay awards of almost 17% over two years, funding schools to improve maternity pay and offering targeted support to normalise flexible working and manageable workloads so that more teachers stay in our classrooms and thrive."
