By Gary Eason
BBC News Online education editor
Teachers who want the government to review its policy of including more children with learning difficulties in mainstream schools have been talking about the problems it causes.
Margaret Morgan now finds herself doubting her efforts
Margaret Morgan, from Ilfracombe in Devon, is beginning her working week at the secondary school where she is the deputy head, but also teaches.
She assumes what she calls her "Joyce Grenfell mode" and enters the classroom.
Pupil A is perfecting his animal noises - he has attention deficit hyperactivity disorder (ADHD) but resists taking his medication.
B is under the table because C is "going to kill him" - yet again. Two more ADHD children.
D is trying out his latest graffiti "tag" on anything he can find. He has a statement of severe learning difficulties: lack of writing skills....
E is in tears because a division sign is on the board and she "doesn't do division". She doesn't read or write either.
F, who is deaf, cannot find his hearing aid - so he can't hear her.
She and her two teaching assistants exchange wry smiles and the lesson starts.
Ms Morgan, attending the NASUWT union's annual conference in Llandudno, says she enjoys her job. Ofsted inspectors have said she is an excellent teacher.
"But I feel more and more that I'm failing.
"I seriously question whether for my students I am able to deliver the quality education they deserve. I question whether I'm doing the best for them.
"How fair is it on them that we expect them to learn in a one-size-fits-all model?"
Her account strikes a chord with other teachers.
Union executive member Amanda Haehner, who proposed the resolution describing inclusion as a "disaster", recognised in it a class that she taught last year.
"We all understood Margaret's lesson - we all have classes like that," she said.
David Mills, from Sutton, said the school in which he used to teach was a non-selective secondary in an area with grammar schools.
As a result, it had to cope - or try to - with a large number of boys with special educational needs.
"The constant struggle to cope got the better of me," he said. "I gather the situation in the school is far from getting better. Somebody needs to help."
But the conference rejected a move to have a limit on the numbers of pupils with learning and behavioural difficulties that any one school in an area should have to take.
Austin Murphy from Leeds spoke of a previously successful school which, due to a reorganisation, had taken in many children with special needs.
"The school is now in chaos. Riots are commonplace and senior management are regularly assaulted," he said.
But a union executive member, Dave Battye, said the idea of a limit was "seductive" but "highly dangerous".
One child could wreck a lesson, he said - but if he was within whatever quota had been agreed there would be nothing the teacher could do about it.
"We wish off-site provision for those who are destroying mainstream schools."
A Leeds teacher, Celia Foote, complained that the conference resolution was full of "generalisations".
She agreed with parts of it.
But it interchanged terms such as behavioural difficulties, disability, special educational needs and challenging behaviour.
"For many of the children I have worked with, who have learning difficulties, inclusion has proved very successful and has not caused problems for the teachers," she said.
Children were part of a community and all members of a community should have the right to attend their local school unless there were good grounds for not doing so.
But Fran Oborski, from Birmingham, said it was not fair on some of them.
She had worked in both mainstream and special schools and had run a unit for children with emotional and behavioural difficulties.
Inclusion might work in primary school but not when children moved on to secondary education, where they felt inadequate and their self-esteem was destroyed.
"They don't want the embarrassment, when they are 14 years of age, of having a special needs assistant tagging along to all their classes, making the difference obvious," she said.
"For some very vulnerable children, inclusion is a form of child abuse or torture."