Private schools associations need to enter the "modern world" by merging more closely, says the new chief executive of the Independent Schools Council (ISC).
Chris Parry told a conference of British international schools this week that the various associations for fee-charging schools needed to stop "going off in different directions" and learn to work together.
His views were echoed by Bernard Trafford, president of the elite Headmasters' and Headmistresses' Conference (HMC), who sees the day when associations such as his no longer exist.
Mr Parry said: "What we are crying out for is unity in the sector. We have a Byzantine way of running the private sector at the moment, which needs to be brought into the modern world."
The ISC represents the UK's seven main independent schools associations and more than 1,280 fee-charging schools, which educate half a million pupils.
Mr Parry, who only took up his role two weeks ago, said he would use the council's annual conference next month to set out plans for how its member associations - including the HMC - should change the way they work.
Although member associations may resist attempts to curtail their individual freedoms, the HMC has already indicated its support for working together more closely.
Dr Trafford told The TES that associations, including his own, might disappear in the future.
"The more we speak as one voice the better - as long as we don't become bland," he said. "If we really get it together, the associations could disappear altogether. That's not to say it's being planned for yet, but it's not inconceivable."
Mr Parry told a gathering of the Council of British International Schools that time was wasted because the different ISC associations did not work together properly.
"Everyone is doing everyone else's homework," he said. "And because of that, they don't have time to do their primary function, which is to teach."
Mr Parry said he wanted the council to carry out more research into private and state sector education, and for it to extend commercial activities.
His comments follow his outspoken debut before the Commons' children, schools and families committee last week, during which he told MPs that thousands of parents were being forced to make great sacrifices to send their children to private schools because the quality of state education was so poor.
In a heated exchange, Barry Sheerman, the committee's chairman, told Mr Parry that his description of private schooling as "paid for" was offensive, because state school parents also paid for their children's education through taxation.
Mr Parry replied that he found it "very offensive" that he could not find suitable state education for his children.
"Where I come from the maintained sector is very poor, and my wife and I have made sacrifices to send both our children to schools in the independent sector," he said. "There are hundreds and thousands of families like mine."
Mr Parry, who joined the ISC after a successful career in the Navy, said there was a "sectarian divide" between private and state schools, which he likened to the Cold War.
He criticised Charity Commission guidance on public benefit tests, describing it as "like a missile from the maintained sector to the independent sector".