The Government's expected to confirm they will be reducing class sizes for students in years 4 to 8 on Monday.

Those year groups have the highest student to teacher ratio, with one teacher to 29 pupils.

NZEI President Mark Potter says that over a generation of teachers have been saying that the teacher-pupil ratio for those students needs to be reduced.

"So it's a very important time for teachers to be able to give the best time they can to children, but it is difficult with so many more children in the class."

LISTEN ABOVE

• School class sizes remain high despite parents paying more money
• Simon Bridges: National will cut primary school class sizes if it gets into Govt
• Professor: National wanted larger class sizes when they were in Govt