No, you cannot read Prince Charles' letters to British government officials.

Attorney General Dominic Grieve on Tuesday overruled three judges who decided last month that the public had a right to see what sort of advice the prince was offering to the government.

Charles has been open about his opinions on a range of subjects. But Britons reading the "particularly frank" letters might not think the prince is politically neutral, as a monarch must be, thus undermining the institution, Grieve said.

"Much of the correspondence does indeed reflect the Prince of Wales' most deeply held personal views and beliefs," Grieve said in a statement setting out his reasoning.

The letters "contain remarks about public affairs which would in my view, if revealed, have had a material effect upon the willingness of the government to engage in correspondence with the Prince of Wales, and would potentially have undermined his position of political neutrality."

Britain's constitutional monarch has no political power, but meets regularly with prime ministers and other senior politicians to talk about events of the day.

Grieve decided that the prince's letter-writing was part of his preparation to succeed his mother, Queen Elizabeth II, to the throne. It's been a lengthy education, with Charles, 63, standing next in line since 1952.

Charles has not been secretive about his opinions on topics such as education, architecture, religion, the environment, organic food and homeopathy. It marks a sharp contrast with his 86-year-old mother, whose personal opinions — except for her Christian faith — are not known to her subjects.

The decision protecting Charles' privacy angered opponents who want more disclosure.

"It's an open secret that Prince Charles lobbies the government," said Graham Smith, chief executive of Republic, a group which wants to abolish the monarchy. "What the public has a right to know is what he is lobbying for and whether he is actually influencing policy,"

Last month's court ruling came in response to requests by The Guardian newspaper, which has been asking for seven years for letters from Charles to government departments.

Several government departments had refused to divulge them, arguing it might breach unwritten constitutional rules on the relationship between the monarchy and the government, and that it would discourage the prince from speaking frankly.