The central North Island's Super Eight schools have joined the boycott of the Auckland private school.
The New Zealand Herald revealed on Wednesday that 10 schools in the 1A competition where St Kents play are refusing to play the school in next year's competition, and several others have followed suit.
Napier Boys' High School headmaster Matt Bertram told the Herald that Super Eight schools would stand with the 1A principals and refuse to play St Kents.
The Super Eight competition includes Hamilton Boys' High School, Palmerston North Boys' High School, Hastings Boys' High School, Rotorua Boys' High School, New Plymouth Boys' High School, Gisborne Boys' High School, Napier Boys' High School and Tauranga Boys' College.
The only scheduled fixture in 2019 involving Super Eight schools is Hastings Boys' High School versus St Kents.
Hasting Boys' principal Rob Sturch is understood to have cancelled the fixture. The school did not return calls made by the Herald.
While the other schools wouldn't normally match up against St Kents during the course of a season, the competition decided to decline any offer if they were approached for a game.
Palmerston North Boys' High School rector David Bovey said the schools came to a unanimous agreement, and that it was a good thing people were talking about the issue.
"As a Super Eight entity we've unanimously agreed to support our Auckland counterparts," Bovey told Stuff.
"If they were looking for fixtures, we wouldn't play them.
"There's been rumours going around about what this school's been doing and what that school's been doing. And I'm hoping what comes out of this is that some schools change the way we're doing things."
St Kents earlier today revealed that they have asked College Sport Auckland to lead an arbitration process to deal with the looming boycott of their participation in the top competition.
Head of St Kents David Hodge said he was confident the issues could be resolved before the start of the season.
"We support a successful school rugby culture and we are delighted College Sport Auckland has confirmed it is ready to act in this role so that we can all look forward to a successful and enjoyable season," he said in a statement.
"We follow the rules that were agreed and set by College Sport Auckland, and would have expected the most recent issue to have been raised before school enrolments had closed for 2019.
"We look forward to resolving this matter and to a successful and rewarding season for all teams."