A strict high school ball dress code has upset students who say they are worried about being turned away from the event if they don't meet expectations.

Kerikeri High School has banned plunging necklines, revealing splits and anything other than ankle-length dresses at the ball.

Suits must be one colour, ties worn at all times and proper dress shoes are required, and any student who doesn't meet the code will not be allowed into the July 27 ball.

Three students, who spoke to the Herald on Sunday on condition of anonymity for fear of being "barred" from the ball, said the dress code was decided by a handful of students and did not represent the majority of the student body who were not consulted.

One of the students said the rules did not accommodate all body types as claimed, meant that students would effectively be hiding their bodies, and that their right to freedom of expression had been undermined.

Students must not show cleavage or have a high split in their dresses which must not go above the ankle at the Kerikeri High School ball. Photo / Newsletter

"By saying they want to be more gender and body inclusive, the dress code they've stated does the opposite of that.

"Because of this, many people go to the ball and feel uncomfortable in what they are wearing."

The Year 13 student said many girls had already bought their dresses online, which cost up to $300, and now had to return them or pay extra for alterations.

"There are girls who've had to send their dresses back because it didn't fit the new dress code and they're worrying about whether or not their dress will arrive before the ball."

The student said her dress was not approved by the dean and she now has to alter it which she felt would ruin it.

"We just want to be happy at the ball, which is one of the defining moments of going to high school."

Another Year 13 student called the dress code "ridiculous" and said there were too many restrictions.

These dresses are out because they feature spaghetti straps, legs seen through sheer fabric and chest cut-outs. Photo / Newsletter

She was anxious about being allowed into the $60-a-head event.

"Being turned down would honestly be devastating and the fact they would do that drives me crazy, because we didn't pay all this money to buy a dress and get dolled up just to be told we don't fit the regulations."

She said the rules were a knock to students' confidence.

"Everyone is so stressed about being turned down. They just stand there and examine you and it's not a nice feeling."

Another student said the code restricted a person's choice over how they could dress.

"The main problem is restricting people's expression of themselves. And another thing you can't do is take your jacket off, or high heel shoes, for the whole night."

The 17-year-old said he went to the Okaihau College ball recently where boys were allowed to wear patterned suits and turtlenecks and the girls could wear any suit or dress as long as it was formal.

"There is definitely a general anxiety around possibly being turned away at the door."

The three students wanted the dress code relaxed.

"I feel like a lot of people would definitely appreciate some kind of loosening of the rules."

The Herald on Sunday emailed questions to Kerikeri High School but principal Elizabeth Forgie said the school no longer wanted to comment.

Boys must wear one-coloured suits, proper dress shoes and a tie at all times at the Kerikeri High School Ball. Photo / Newsletter

Previously Forgie told the Herald on Sunday the dress code was driven by students and there had been no feedback, leading her to believe the dress code advisory group had adopted the right tack.

"The students wanted something that was going to be more inclusive."

She said at the time it was not gender specific, and catered to all body types, bodies of all "shapes and sizes".

Forgie said two weeks ago that the ball had always been a very formal occasion but this year students decided to articulate the dress code to avoid any confusion or anyone being sent home.

"The last thing the students wanted is that someone might misinterpret what has always been a written guidance and we don't want to spoil anybody's night."