A Hastings principal has slammed an increasing number of parents taking kids on holiday during term time, arguing it could ruin their kids' and the school's future results.

St John's College principal Paul Melloy, who is currently in Chile on a tour with the school's first XV rugby team, said in the school's April newsletter that attendance was now one of the biggest issues in modern education.

"Schools have to keep on top of it or their pupils will fail," Melloy said.

"We are delighted by our NCEA results in recent years, and we do not want poor attendance to affect these results and the 'futures' of our pupils.

"The letter to parents was an proactive reminder of the importance of school attendance and asking for their support. We cannot do it [alone], only as a community we can."

St John's College principal Paul Melloy is not afraid of broaching "uncomfortable" home-truths. Photo / Duncan Brown

Melloy and deputy principal Rob Ferreira wrote in the newsletter that while the topic of absenteeism and academic performance was "uncomfortable" it had to be discussed.

"St John's College now has a growing list of pupils who take 'time' off school.

"Some of this behaviour is enabled by their parents or guardians and it is having a huge effect on their son's education.

"Last year we pleaded with parents not to take their sons on holiday during school term to no avail. This list in Term 1, 2019 is concerning."

The newsletter goes on to state that the biggest issue is the not the time taken off, it's the priority given to holidays.

"The biggest issue with holidaying during school time, in our opinion, is not the actual time off school.

"It's the priority the holiday is given above school attendance. This, in your son's mind, lowers his perception of the importance of school attendance. This is dangerous.

"We are, again, pleading for your support. Please do not let your son take unnecessary days off school.

"If he is absent, please ensure he catches up on missed work. And please do not take holidays during school time."

According to Ministry of Education's Education Counts website. a sustained absence from school does affect educational achievement and can lead to significantly diminished opportunities later in life.

A New Zealand study (Hughes, 1999) found student attendance during Year 11 to be one of the most significant variables influencing student achievement in senior secondary school.

The study showed students with low attendance and lower reading achievement had the highest risks for adverse outcomes.