Minister for Education Richard Bruton has no plans to change the junior cycle to prevent thousands of students losing 10 per cent in their English exams next summer due to a union dispute.

The reformed junior cycle, which seeks to provide a much broader assessment of students’ achievements, is being rolled out across all secondary schools.

However, the biggest secondary teachers' union, the Association of Secondary Teachers in Ireland (ASTI), has directed members not to take part in any classroom-based assessments linked to the changes.

The English exam is the first subject to be fully rolled out this year for third-year students.

But pupils in about two out of three secondary schools, or at least 40,000 students, will not be able to take part in classroom-based assessments which aim to capture students’ oral communication and writing skills due to the union’s stance.

A written assignment requiring students to reflect on what they have learned is worth 10 per cent of the final written exam.

At an Oireachtas education committee on Thursday, Fianna Fail's education spokesman Thomas Byrne questioned whether it was fair that students should be "penalised" over the dispute.

“Normally in an industrial relations dispute, it’s the people who strike who lose out - but in this case it will be the students,” he said.

However, Mr Bruton said the junior cycle changes were public policy and have been rolled out in schools.

He called on the union to drop its ban on co-operating with classroom-based assessments for the English exam and to engage over further talks.

“These assessments were set many years ago. It was agreed with all the unions at the time and it is now established public policy,” he said.

The ASTI’s opposition to the junior cycle changes stems mainly from its belief that teachers should not have to mark their students’ work for State exams.

Principals, teachers and school management bodies, however, say they are coming under criticism from parents over fears that junior cycle students are set to lose out on marks later this year.

In a notice to ASTI English teachers this week, seen by The Irish Times, the union has told members it is "doubtful" that the Department of Education will allow students to lose these marks.

“Regarding speculation that students will be deprived of 10 per cent of the marks in the subject, this presupposes that those charged with setting and administering the examinations will fail to intervene,” the circular states.

"One imagines that the likelihood of such a dereliction on their part is doubtful. ASTI has called on the Department of Education and Skills together with the State Examinations Commission to clarify the position in order to ease the anxieties of parents, teachers and students that are currently growing in intensity."

Junior cycle students studying English face two classroom-based assessments, one an oral communications task which was due to have been conducted last May.

Due to the dispute, schools have been given a second chance to complete this by the end of this month. However, the ASTI’s ban remains in place.

Students are due to complete a second classroom-based assessment by early December, which is collection of students’ writing, followed by a written reflection on their learning.

These classroom-based assessments will be marked by teachers themselves and will go towards a new “junior cycle profile of achievement”, which seeks to capture students’ progress across a much broader range of areas. They will be marked by descriptions - such as "met expectations", or "exceeded expectations" - rather than traditional grading.

The written reflection, on the other hand, will be marked externally and is worth 10 per cent of the final written exam.

Students in ASTI schools will not be in a position to complete this, or any of the classroom based assessments, due to the union ban.

They will, however, be taught the new curriculum as the union ban does not extend to this area.