Teachers say they are struggling to cope with rising numbers of children with special educational needs in mainstream schools, according to a survey by the NUT.
Despite widespread support for the principle of inclusion, the poll of 359 staff found that three-quarters of teachers wanted more back-up in the classroom, two-thirds said they needed training and half said they had no time to prepare suitable resources.
One primary teacher from Wokingham told the survey: "I do believe that everyone has a right to be included. However, I truly worry that sometimes children with severe needs take priority over the rest of the class.
"Too many times now I have had to explain to children not to be too cross that they have been hit, kicked, bitten or spat at, but to ask them to try and understand that the other child finds things difficult. I have a duty to make sure that every child is safe, SEN or not."
The union also warned that government moves towards giving parents more rights will not solve the problems of funding and training.
Christine Blower, general secretary at the NUT, said: "More teachers want to see more classroom support inside their schools rather than increased separate specialist provision - showing teachers' commitment to including kids if they only could."
The survey of 359 staff in both primary and secondary schools found that 92 per cent did not have a specific SEN qualification. Among those who did, the most common training was in dyslexia.
Even among special educational needs co-ordinators, only one in three had a related qualification - but this will be made mandatory for all new Sencos.
The survey also concluded that teachers were particularly concerned that more children are being identified with emotional, behavioural and social difficulties or on the autistic spectrum.
It revealed that more than half (52 per cent) had noticed an increase in numbers of SEN children in schools, while only 10 per cent considered that no real change had taken place.
Official government statistics show there has been a rise in the number of SEN children without statements, from around one in seven of secondary pupils to almost one in five during the past five years.
There has also been a rise from 16.5 per cent to 18.2 per cent of primary pupils.
But the proportion of children with statements in mainstream primaries and secondaries has fallen slightly over the same period.
Most teachers said there was a small group of SEN pupils in their class, but in Haringey there were 26 teachers (35 per cent), who said up to half the class had SEN.