More than half of parents would send their child to private school if they could afford to, a poll suggests.
Many believe that fee-paying schools provide a better standard of education, according to the survey, commissioned by the Independent Schools Council (ISC).
And some thought they offered smaller classes, and a better start for their youngster.
The survey found that of the 590 parents questioned, 57% said they would educate their child privately if they had the money.
This has risen from 51% who said the same in 1997.
Of those that would send their child to private school, 51% said these schools had better standards of education, 15% said they would educate their child privately because they have smaller classes and 14% said it was a better start to life.
In total, 2,075 adults were questioned, with nearly three in five (59%) said educational standards in state schools are lower than the standards in fee-paying schools, while 23% said that they are about the same, it found.
Just 6% said that standards are higher in state schools, and the rest did not know.
Rudolf Eliott Lockhart, the ISC's deputy general secretary and head of research, said: "This survey shows that the public increasingly recognise the exceptional quality of education provided by independent schools.
"The strength of these schools lies in their ability and commitment to offer a bespoke education to their pupils, giving them the very best start in life.
"That more parents than ever would like to send their children to an independent school is clearly reflected in the rise in pupil numbers in ISC schools this year."
The ISC represents eight private school associations collectively educating more than half a million children.
Almost half of private school staff say that their school has already started, or is about to begin building new facilities such as swimming pools, sports halls, classrooms, science labs and theatres, according to a separate survey by the Association of Teachers and Lecturers (ATL).
More than one of the 1,500 teachers questioned mentioned schools building new rowing facilities, and one said their school was developing a go-kart track, ATL said.
The union suggested that schools were investing in facilities to attract parents, and could help private school pupils to win more Olympic medals in the future.
Recent research found that more than a third of Team GB's medallists this summer were educated at private school.
ATL general secretary Dr Mary Bousted said it was "wonderful" that many schools could afford to up-grade facilities.
But she added: "Schools must not loose sight of their most important asset, their staff. Shiny new sports halls and rowing clubs are great, but without their dedicated staff the pupils would not be able to reach their potential.
"While fees go up to pay for these facilities, staff are seeing their living standards fall as their pay is frozen or increased at a rate below inflation."