British authorities on Thursday released more private letters from Prince Charles to government ministers on topics ranging from historic buildings to hospital food.

The letters were the subject of a lengthy legal battle that pitted Charles' right to privacy against the public's right to know.

The Guardian newspaper had applied to see correspondence between Charles and government departments. The government refused, arguing that the frank missives reflected the heir to the throne's personal views and publishing them could undermine the perception of his neutrality.

As king, Charles would be expected to keep out of politics. As prince, he has expressed strong opinions on topics including architecture, genetically modified crops and climate change.

The Supreme Court ruled against the government in March, and a batch of 27 letters was released last month.

The 17 published Thursday — six from Charles, eight from ministers and three from private secretaries — were written between 2007 and 2009.

They reflect the prince's well-known views on topics including food in hospitals and affordable rural housing. In one letter, Charles discusses his support for complementary medicine, which he says he has maintained despite "waves of invective over the years from parts of the Medical and Scientific Establishments."

Another speaks of the prince's concern about historic sites "lying derelict and abandoned by unscrupulous owners."

The missives are less dramatic than those released last month, which included a letter to the prime minister about resources for troops in Iraq and an appeal for funds to preserve the huts used by early 20th century Antarctic explorers.

Charles' Clarence House office said the letters showed "the range of the Prince of Wales' concerns and interests for this country and the wider world."

The responses from ministers were generally long and considered, and ended with varying degrees of formality. Health Secretary Alan Johnson signed himself "yours sincerely," but his successor Andy Burnham was more florid.

"I have the honor to remain, Sir, your Royal Highness's most humble and obedient servant," Burnham wrote.