Clarence House has made another robust defence of the Prince of Wales's right to write to ministers as a second batch of his private correspondence was published.
Six letters written by Charles have been published by the Government and will throw further light on his dealings with ministers.
The topics covered by the letters, written between 2007 and 2009, range from hospital food to affordable rural housing and climate change.
Clarence House said in a statement that the correspondence showed "the range of the Prince of Wales' concerns and interests for this country and the wider world".
The statement added "The letters published by the Government show the Prince of Wales expressing concern about issues that he has raised in public like affordable rural housing, the quality of hospital food, the preservation and regeneration of historic buildings, an integrated approach to healthcare, climate change, and others.
"In all these cases, the Prince of Wales is raising issues of public concern, and trying to find practical ways to address the issues."
In one letter, released today almost exactly six years after it was originally sent to then-Culture Secretary Ben Bradshaw, Charles asks the Labour MP to get in touch and "discuss various heritage matters".
The letter, dated June 16 2009, came a week after the Exeter MP was handed the role of Secretary of State for Culture, Media and Sport.
In it, Charles briefly detailed his concerns about "major historic sites, many of which are lying derelict".
He also hit out at "unscrupulous owners" for abandoning certain unnamed sites.
He wrote: "My Regeneration Trust has worked for many years now to help initiate such schemes and my experience has invariably been that they are a great success.
"As many of these historic sites are often in fairly deprived areas, their revitalization can make a big difference. Not only that, but I do feel we owe it to those dedicated craftsmen who built the buildings in the first place, and many of whose descendants probably still live in the area, to bring their dedicated workmanship back to life."
A Clarence House spokesman described the Prince of Wales as "a passionate believer in the role of historic buildings", and cited The Prince's Regeneration Trust - formerly known as The Phoenix Trust - specifically to find new uses for derelict buildings or those at risk of becoming so.
There is no record of any response from Mr Bradshaw released in today's disclosures.