The Association of Teachers and Lecturers unveiled the Support Staff Charter at its annual conference in Liverpool.
The Charter covers issues such as pay, working hours, training, and violent and abusive behaviour and was published as delegates at the conference raised concerns about poor practice in schools.
A motion before delegates called on the ATL to investigate the number of support staff in schools who are being used to cover classes and to campaign for a statutory right to training and development.
The motion stated: "Conference deplores the misuse of support staff in schools to cover for teachers at short notice and for protracted periods.
"Conference notes that increasingly support staff employed to support the learning in class, with groups or with individuals, are being withdrawn from this valuable work to cover absences for several days, thus depriving one group of the support they deserve and depriving another class of a qualified teacher."
There are around 900,000 UK school support staff, a workforce made up of teaching assistants, librarians, technicians, administrators, dinner ladies, caretakers and other workers.
On pay, the Charter states that levels are too low for the roles and responsibilities held by support staff and there are inconsistencies in pay. It also calls for a national pay framework for support staff roles.
On working hours, it urges schools to tackle the "unpaid overtime culture" that affects many support staff.
On training, it warns that support staff are "often overlooked" when schools organise and fund training and CPD.
On abusive behaviour, it states: "Support staff are often in the frontline of physical and verbal attacks from pupils and many get little or no support from school managers."
Tina Lauder, a higher level teaching assistant in Doncaster, said: "The politicians need to sit up and take notice of the innumerable injustices faced by support staff in schools throughout the UK. I urge them to read (the) Support Staff Charter and promise to make changes to improve the lives of support staff."
Dr Mary Bousted, ATL's general secretary, added: "In spite of the lip-service paid by school management and politicians to the importance of support staff, they are still too often treated as second-class citizens.
"Despite the vast increase in the roles and responsibilities of support staff, their pay remains woefully inadequate, with many stuck in a permanent poverty trap."
A copy of the Support Staff Charter can be found at www.atl.org.uk/supportstaffcharter