The correspondence – known as the “black spider” memos because of the heir to the throne’s unusual handwriting style – was sent between September 2004 and March 2005, when Tony Blair was prime minister reports Sky News.
The 27 letters were published by the Guardian, the Information Commissioner and the Cabinet Office on Wednesday afternoon.
They reveal a keen working relationship between the Prince of Wales and Mr Blair.
In one memo, Charles lobbied Mr Blair to replace Lynx military helicopters and said Britain’s armed forces were “being asked to do an extremely challenging job (particularly in Iraq) without the necessary resources”.
He also warned of Britain’s lack of self-sufficiency in producing meat and vegetables, and urged Mr Blair to bring in a badger cull.
After a lengthy appeal process, the UK’s highest court, the Supreme Court, finally agreed to quash the ban on their publication last month.
The Government’s attempts to block their release has cost the taxpayer more than £400,000 in legal fees, The Guardian reported.
The money was spent by eight government departments as former attorney general Dominic Grieve tried to stop their publication, claiming it would undermine the principle of the heir to the throne being politically neutral.
The newspaper’s editor-in-chief Alan Rusbridger said: “We fought this case because we believed – and the most senior judges in the country agreed – that the royal family should operate to the same degrees of transparency as anyone else trying to make their influence felt in public life.”
A Clarence House spokesman said the letters show Charles “cares deeply about this country and tries to use his unique position to help others”.
He said: “The publication of private letters can only inhibit his ability to express the concerns and suggestions which have been put to him in the course of his travels and meetings.”
Sky News’ royal commentator Alastair Bruce said: “He is a private citizen like you and me and he is allowed, like you and I, to write to ministers.
“The Prince of Wales gets to visit parts of British life that is incredibly wide. I don’t think from what I’ve heard so far that the Prince of Wales has taken on a political stance here.