School governors in Jersey have said States schools will face bigger class sizes and fewer teachers if subsidies to fee-paying schools are not cut.
Governors of Grainville, Le Rocquier, Les Quennevais and Haute Vallee have joined the debate over funding cuts.
They described it as "insulting" and "denigrating" to hear some fee-paying parents claiming to struggle to do the best for their children.
The governors said that savings within education had to be made somewhere.
Jersey's education minister wants to cut the subsidy to fee-paying schools by 50% as part of wider government savings across all departments.
Grainville governor Katie le Quesne said if they had to make further cuts it would badly impact on children in the States schools.
She said: "In the States sector we have saved £1.8m in the past five years in the way we run our schools and we still deliver a good education.
"In the private sector the fee-paying schools have saved about £200,000 in the same period so it is wildly disproportionate already, the amount of savings that have been made."
In an open letter to States members, the governors said that money cut from the budgets of the States secondary schools instead of that of private schools could have a huge impact on the ability of children there to succeed in life.
The letter said that unlike the fee-paying schools there is no alternative source of income for States schools apart from government funding.