The Prince of Wales has defended his beliefs about modern education, after he was accused of being "out of touch".
Charles did not speak to reporters at Lambeth Palace
A private memo, which emerged last week, led to critics suggesting that the prince believed people should not rise above their station.
Prince Charles told a meeting of bishops at Lambeth Palace that was a "travesty of the truth".
"Ambition should never be constrained by a person's starting point in life," he told the seminar.
No reporters were allowed to hear the speech, but a text of Prince Charles's remarks was released beforehand.
BBC Royal correspondent Peter Hunt said it was out of the ordinary for the prince to make such a move.
"It's unusual for Prince Charles - no stranger over the years to criticism - to respond so publicly and so quickly," he said.
"It's an indication of how damaging he and his new breed of advisors regard the situation."
The prince's communications secretary Paddy Harverson, who was also at Lambeth Palace, said Charles was making the speech in order to "clarify" his position.
Charles stayed for two hours at the palace, where the Archbishop of Canterbury Dr Rowan Williams was holding a seminar on charity work attended by 28 bishops.
He did not address the assembled media pack upon his arrival or when he departed.
One bishop who heard the speech, but who did not want to be named, said: "It was very good. It was very interesting."
Another said: "There was nothing controversial in it whatsoever. It was off the record."
According to the leaked extracts of his comments, the prince told the bishops: "For the last 30 years, I have done all I can to give young people who have limited opportunities, usually through no fault of their own, a chance to succeed."
Dr Williams was holding a seminar on charity and voluntary work
"Often all that is needed is the right help at the right time for them to make the most of [their God-given ability]," he said.
"What these young people have in common is not just a natural talent, but the
determination to succeed through hard work. That is the combination that breaks down the barriers to success."
"Not everyone has the same talents or abilities, but everyone, with the right nurturing, can make a real difference to their communities and to the country.
"Ambition is a good thing and should never be constrained by a person's starting point in life and people must be encouraged to fulfil their aspirations in ways that recognise their different abilities and talents."
He defended himself against the accusation of being old-fashioned, saying he was aware that his views were portrayed that way.
"They may be. But what I am concerned about are the things that are timeless regardless of the age that we live in.
"Also I have been around long enough to see what were at the time thought of as old-fashioned ideas now come into vogue."
Education Secretary Charles Clarke had accused the prince of being "out of touch", but welcomed the comments made in the speech.
Mr Clarke told BBC1's Breakfast with Frost on Sunday that the remarks had his full support and the prince had now made clear his feelings on the issue of ambition.