Some South Auckland principals want to cancel this year's external exams for Auckland students because many are staying at home to "choose life over education".

Even now that Auckland's level 3 lockdown has ended, some schools still have only a third of their students back in class because of community fear of Covid-19, which has hit mainly Pasifika and Māori families this time around.

Time to catch up is fast running out with school holidays beginning on September 25 and National Certificates of Educational Achievement (NCEA) external exams due to start on November 16.

Sir Edmund Hillary Collegiate principal Kiri Turketo, who has seen attendance in her senior school grow only from 28 per cent on Monday to 30 per cent on Wednesday, said the outlook for her NCEA students was "dire".

"They are choosing life over education," she said.

She said South Auckland principals asked Government ministers and officials in a Zoom meeting during the lockdown to let schools grade all students for NCEA this year based on their previous work, rather than the usual external exams.

"We are all saying why can't you leave it to teacher judgment based on derived grades?" she said.

She said the NZ Qualifications Authority told Auckland schools on August 24 that they could deliver this year's Maths Common Assessment Tasks (MCAT) by derived grades if their students were not ready for the MCAT exams on September 15 and 17.

The agency said: "Where a school or kura has been operating under alert level 3 conditions during term 3, but has moved into level 2 prior to the MCAT, and students have had adequate opportunity to prepare for the assessment, schools should make all reasonable endeavours to deliver the MCAT as planned.

"In circumstances where it would not be reasonable to proceed, or where the school determines it would not be reasonable to expect some or all of your students to be ready for the assessment, you should use your missed assessment policy to determine a valid grade for any student not sitting the MCAT."

Turketo commented: "If they can do that for MCAT, why can't they do that for NCEA?"

Howick College principal Iva Ropati, who has more than 90 per cent of his students back, said proceeding with external exams would be "terribly unfair" to Auckland students who have lost almost nine weeks of classes this year, compared with six weeks in other regions.

"I'd like to see derived grades to be considered with no external exams," he said.

"Just go off what the kids have done for their programmes to date, and let us as the teachers decide what a judgment could be for their achievement, knowing that they have missed a good chunk of the time, particularly for Auckland students - in fact only for Auckland students."

However the call is not supported by most principals in the wider Auckland region. Auckland Secondary Schools Principals Association president Steve Hargreaves has asked for four extra NCEA credits for Auckland students, but said the exams should go ahead.

"I think it is important we sit the exams," he said.

"The UK had a shambles with widespread use of derived grades. The NCEA exams are two and half months after our return to school, which is enough time to focus on essential course content and prepare for the exams.

"If we used derived grades we would have to generate evidence of student performance – which is likely to be an exam anyway."

Hargreaves' school, Macleans College, reports attendance now "well into the nineties".

Aorere College principal Greg Pierce, whose attendance is still only around 50 per cent, said scrapping the externals had some support but Auckland schools generally were diverse and many schools would want to keep them.

De La Salle College principal Myles Hogarty, who has 95 per cent of his students back, said his staff would offer extra tutorials and class time in the holidays to prepare students for the exams.

"We are preparing our boys to sit external exams," he said.

Turketo said her staff had proposed using a week of the school holidays to continue classes for all students who want to attend on a voluntary basis.

"The staff said, why don't we work for one week, have it as a week 11 [of this term]? I have to admit I shed a tear, I felt so proud," she said.

"I know that we have board support, I know that we have teacher support. The question I have to be realistic about is that we are already at we are already at week 7 and I only have 28 per cent of the kids."

A spokeswoman for Education Minister Chris Hipkins said Hipkins was "looking at whether any further support needs to be put in place" for Auckland NCEA students.