Attempts to improve secondary teachers' working lives are doomed unless radical steps are taken to reverse the decline in pupil behaviour.
This was the verdict of academics from Cambridge university, who were commissioned by the National Union of Teachers to examine government initiatives on secondary education.
Their report said moves to reform school staffing would not succeed in cutting workload because teachers were swamped by worsening discipline problems.
The sharp decline in behaviour during the past 15 years was blamed on the "overloaded" curriculum for 11 to 14-year-olds, parental attitudes, large class sizes, inclusion strategies and the lack of time teachers had to talk to pupils and each other.
"The low points in most teachers' lives arose from the deterioration in classroom behaviour resulting in a constant battle 'to be allowed to teach'," said the report. "Nearly all teachers now had some pastoral responsibilities and the administrative workload attached to dealing with difficult, disengaged or disruptive pupils took up most of their non-teaching time."
It said the Department for Education and Skills would be better off if it spent the millions of pounds used to help schools meet test targets for 2006 on investigating ways to improve pupil behaviour.
Teachers welcomed many changes introduced to lessen their workload including extra support from teaching assistants and the ability to let others do their administration tasks, the researchers said. But, they added these changes "will not in themselves remove the main factors which contribute to the present overload and stress experienced by many teachers."
The report said that so far the workforce agreement has had little impact on workloads. "The main improvement has been to reduce cover to one period per week and to provide some clerical support."
The academics, led by professors Maurice Galton and John MacBeath, based the study on questionnaire responses from 233 teachers in 65 schools.
The Government said the report did not provide a balanced picture of life in schools because its sample was less than 0.05 per cent of teachers.
The report says that bad behaviour was the worst obstacle to teaching, followed by a lack of discussion time and large class sizes.
The results were slightly different for grammar-school teachers, who ranked too many national initiatives as their main worry. The chief concern for special school staff was lack of time for discussion.
Pay was not a real issue, ranking 10th out of 15 main obstacles to teaching.
The report says teachers work between 45 and 70 hours per week. Outside lessons and "directed time" they spend an average 22.1 hours on other work-related activities such as preparing materials and displays (6.1 hours) and marking (5.3 hours). Two years ago, the School Teachers' Review Body recommended that the DfES reduce the average weekly term-time total of 52 hours.
Inspection was the initiative teachers disliked most. The most popular was the national curriculum, approved of by 65 per cent of teachersnmladd.
The report, however, recommended urgent modification of the key stage 3 curriculum to give teachers greater freedom and pupils more enjoyment.
The national curriculum was most popular with younger staff, although some headteachers feared newly-qualified teachers used it "like a security blanket".
The Government said the report did not provide a balanced picture because its sample was less than 0.05 per cent of teachers.
A Life in Secondary Teaching: Finding Time For Learning will be available in the next fortnight at www.data.teachers.org.uk