However, according to Supreme Court rulings SCFR 32/2011 and SCFR 35/2015, the maximum number of students allowed in a classroom at the present stands at 35, secretary of the Ceylon Teachers Union - Joseph Stalin says.
By reducing the number by one child each year from 2016, the number had been reduced to 36 in 2020, he added.
In addition, a group of old boys from Royal College had further strengthened this Supreme Court ruling, in a case at the Appeal Courts last year, he said.
Therefore, if the education ministry attempts to violate this, will seek legal redress against the minister and ministry officials over defamation of court, Stalin said to 'Sri Lanka Mirror'.
However, Ministry Secretary Kapila Perera had said that in view of the demand to get admissions to national schools, the ministry was seeking cabinet approval to get the number officially increased to 40.
He had noted that certain schools are already having more than 40 students in a classroom.
Last week, the government stopped admission of students to intermediate classes of national schools until further notice.
Accordingly, no admissions can be made between grades 2 and 5, and grades 7 and 10.
In terms of new criteria to be prepared, the admission quota for selected categories will be retained.
A ministry appeal board will be set up to address issues if applicants are unable to get admission to the school of their choice.
However, teachers unions charge that these measures are being taken with the ulterior motive of admitting students to schools through letters issued by ministers.
Charging that the appeal board is being set up for this purpose, they also warn that this could again see a rise in obtaining bribes to admit schools to national schools.