HALIFAX -- Nova Scotia has announced a new policy allowing high school teachers to fail students who miss one fifth of their classes, in an widening effort to combat absenteeism.

The Liberal government announced the measures Wednesday, saying more than 29,000 students out 118,000 are absent more than 16 days a year of school.

Education Minister Zach Churchill said he's hoping a mixture of more early intervention and stronger consequences will start reversing those figures.

"We think this will put more kids in our classrooms," he told reporters in Halifax.

The new 20 per cent threshold has some flexibility, particularly in circumstances such as illness, a department spokeswoman added later.

The attendance policy is based on recommendations from the Council to Improve Classroom Conditions the Liberals set up following labour strife with the teachers' union earlier this year.

During the labour dispute, teachers testified before a legislature committee that they often had little ability to penalize students who didn't turn up. The union said its members were feeling pressure not to fail students.

Churchill said the government's new policy begins Oct. 1 and will result in students being marked absent unless "they are attending an activity that directly relates to their learning, or a school activity."

Teachers are also expected to come up with approaches to address absenteeism in "early and targeted interventions" for children in elementary and middle schools, said the minister.

Students in Grades 10 to 12 could lose their credit if they exceed the 20 per cent benchmark. That's 37 days of a regular school year.

Michael Cosgrove, a Halifax high school teacher who is a member of the classroom council, said teachers have been noticing a drop off in attendance in recent years.

However, he said since word of the policy has been circulating, more students are coming to classes at his school.

"We've been in school for three weeks and I've been noticing a difference," he said.

The teacher said the new policy adds accountability to ensure older students attend.

"We'll make accommodations for vacations ... or a team, but how about you make accommodations and we put more of a focus on attending and you work around us," said the teacher.

Cosgrove said it's extremely rare that a student misses one fifth of classes and still does well.

In the exceptional case where this occurs, Cosgrove said missing one fifth of classes would remain a legitimate reason not to give a student the credit.

The policy also provides for teachers to give students the lessons they miss, with the expectation the students will catch up on their own time.

Churchill said the department also has accepted the council's recommendations to create pilot projects where support staff will work with students for whom attendance becomes a concern.

Liette Doucet, president of the Nova Scotia Teachers Union, said the changes will help reduce teachers' workload.

"One of the reasons the workload is high is because students are absent and they (teachers) are trying to catch those students up and create lessons that will help students," she said.

"It will give them the ability to work with the principal and ensure the students are present."

The official Opposition's education critic said absenteeism is partly due to curriculum problems and a lack of vocational programs.

"One avenue we can go down is to start to discuss programming in our schools. Quite honestly there are students who are disengaged," said Tim Halman, the Progressive Conservative member of the legislature for Dartmouth East.

He also said it's unclear how thoroughly the policy will be enforced.

Claudia Chender, the NDP critic, said if Nova Scotia wants to see improved attendance, it will also need to do more to reduce the root causes of poverty and mental health supports.