Students or parents who try to influence calculated grades for the Leaving Cert will be reported to the Department of Education.
New guidance issued to teachers says any sort of pressure or inducement - such as gifts - could undermine the new system.
Cabinet has also decided to indemnify teachers and school leaders against any legal action relating to the marks they give.
Education Minister Joe McHugh today said no student or parent should try to influence the calculated grades.
He said: "I want to emphasise that canvassing will not be tolerated.
"We do have [reporting] mechanisms within the guidelines now that will allow for persistent contact - either directly from students or on behalf of students."
Minister McHugh said the aim of the guidelines is to provide "clear and precise guidance" to teachers.
However, he stressed that "fairness and the interests of the students" have been at the centre of all decision making.
In terms of external candidates, the Department says it will at those students "on a case by case basis and will be flexible".
The guidance published today also provides guidance on how teachers "can work together to ensure alignment of marks across students and classes in schools".
Minister McHugh yesterday assured students that their grades would not be based entirely on mock exam or junior cycle results.