He has aligned himself with the fee-charging Manchester grammar's scheme to compensate for the loss of public funding that enabled children from poor backgrounds to attend the school.
One of the Labour Government's first acts was to scrap assisted places, re-directing pound;100m into cutting infant class sizes. Critics of the scheme said it helped the middle classes, not the poor.
Teachers' union leaders have questioned the Prince of Wales's role in the appeal. Nigel de Gruchy, general secretary of the National Association of Schoolmasters Union of Women Teachers, said: "I'm a bit surprised as this is quite a political gesture on his part."
John Dunford, general secretary of the Secondary Heads Association, said:
"I hope very much that he will be open to appeals from schools which also want to serve a wide social mix."
Prince Charles said on a visit to the school last week that he was pleased to be supporting the principles of the school's founder that quality education should be "available to everyone regardless of class or creed".
The bursary is already funding 39 pupils this year, and another 42 places will be offered for September at the pound;5,100-a-year school.
Ian Thorpe, deputy head, acknowledged the Prince's role could be politically sensitive. He said: "He was very brave to take it on. I think he sees it as giving boys the opportunity of advancement and betterment, similar to those being offered in his Prince of Wales Trust for older children."
Pupils benefiting from the bursary will have to pass an exam and a means test.
The school has appealed to Old Mancunians, including actors Robert Powell and Ben Kingsley and cricketer Michael Atherton. Children's author Alan Garner has donated the first year's royalties from his new play Holly from the Bongs. The play will be premiered by the school at the Library Theatre in July.