Rotorua principals say it will be far easier for children to bring drugs to school if the Government goes ahead with a new bill.
The Education Amendment Bill, which was introduced to Parliament this month, aims to abolish the use of drug sniffer dogs and drug testing in schools.
The Ministry of Education says the changes will encourage safe learning environments without invasive methods but local principals disagree.
John Paul College principal and New Zealand Secondary Schools' Principals Association president Patrick Walsh said the bill "appeared out of nowhere", with no consultation given to principals or school representatives.
He said the bill would make it easier for children to bring drugs to school because deterrents were taken away, like drug testing and random searches.
"We all know there is a problem with drugs in the community and parents have an expectation that schools will be drug free.
"[This bill] seems contradictory from the Ministry of Education which says they want to keep schools safe from drugs."
Mr Walsh said currently schools could use drug testing and urine samples as a condition for suspended students returning to school who were caught with drugs.
He said if the bill was passed, schools would be unable to suggest drug testing as a deterrent.
He said that unlike the Government, school principals he had spoken with did not see the current laws as a breach of privacy.
"We do not think it is a breach of the Bill of Rights Act and it has never been tested in the courts as a breach of privacy ... we think it is both necessary and reasonable."
He said he would be meeting Education Minister Hekia Parata next month to discuss the bill on behalf of the Principals' Association. The Ministry of Education, in a statement released on their website, said the changes helped schools provide safe learning environments without invasive methods.
"[The bill] gives teachers sufficient powers to keep their students safe and well managed, while not breaching the rights of those students."
Under the new bill, teachers will still be able to take reasonable steps to make students surrender items, confiscating and disposing of items where appropriate.
However, the bill will prohibit searching a student through the use of force, random or blanket searches, the use of drug dogs and the collection of bodily samples.
Rotorua Lakes High School principal Bruce Walker said they regularly and successfully used drug dogs at the school, which acted as a "symbol" to students.
"[The drug dog] sends out a strong message, the students know and parents know that if the dog finds drugs we will deal with it through our school procedures and then through the law of the land.
"We believe schools should be drug free and this bill is going to make it far easier for children to bring drugs to school."
Mr Walker said they had never received a complaint about the use of a sniffer dog, which visited the school at least once a term.
Submissions for or against the bill close on January 24, with a report due out in April.
Earlier this year The Daily Post reported that 73 students were stood down or suspended for drug-related incidents in Rotorua schools during 2011, nearly double the national average.