The cache of 27 letters, including 10 written by Charles personally, includes letters written a decade ago to former Prime Minister Tony Blair and other top officials on topics that include agriculture, redevelopment in Northern Ireland and other matters. The British press has dubbed them the "black spider" memos, due to the handwritten greetings and closings that Charles wrote in his familiar cramped style.
The letter-writing is controversial because as future king, Charles is expected to remain neutral on political topics.
In the memos, the sometimes quirky prince, known for his commitment to organic farming and traditional architecture, freely expresses himself on matters like badger culling, the readiness of the Armed Forces and standards for the use of alternative medicines.
In one letter to Blair on Sept. 8, 2004, the future king and military veteran raises concerns about the British Armed Forces not getting enough resources. He mentions delays in delivering military aircraft due to budgetary pressures.
"I fear that this is just one more example of where our Armed Forces are being asked to do an extremely challenging job (particularly in Iraq) without the necessary resources," Charles wrote.
Funding levels for the military is a political topic for any country's government.
The British government tried for years to keep the letters secret — fearing that publishing them might damage public perceptions of Charles' neutrality — but eventually lost a Freedom of Information case brought by The Guardian newspaper.
Charles' press office issued a statement Wednesday defending the letters. It said Charles was "raising issues of public concern and trying to find practical ways to address the issues."
The royal statement said Charles was expressing concerns about issues that he has raised before, including "the state of farming, the preservation and regeneration of historic buildings" and other matters.
Charles had earlier said he is unhappy that his privacy was not protected. The government has also indicated it may tighten rules to protect future royal communications from release under the Freedom of Information act.
There were signs of tension Wednesday as an angry senior press officer working for Charles tore the cover off the microphone being used by a TV reporter who asked the prince about the letters.
The government was ordered to release the letters in 2012 after losing its court case. But the attorney general vetoed the decision, arguing that Charles' letters were part of his preparation to become king and should be kept private.
That was upheld by one court, but then overturned in 2014 by the Court of Appeal, which decided there was no justification for overturning the earlier decision. Britain's Supreme Court in March supported that ruling, leading to Wednesday's publication of the memos.