The Palace has defended the Prince Wales' frequent meetings with Cabinet ministers as a part of his 'duty'.
The Prince of Wales has held 36 private meetings with Cabinet ministers since the last general election.
- Charles has had seven private meetings with Prime Minister David Cameron
- He has had talks with Labour leader Ed Miliband on three occasions
- And privately spoken to Nick Clegg once
A Clarence House spokesman said the Prince has a "duty to communicate privately with the Government on any matter he chooses".
The Prince is known for his strong views on green issues and rural affairs but is meant to be politically neutral in his role as heir to the throne.
Last month, the Attorney General's decision to block public disclosure of letters Charles wrote to Government ministers was upheld by three High Court judges.
Anti-monarchy group Republic accused the Prince of dishonesty and said he was only meeting ministers from departments relevant to his own interests.
Republic chief executive Graham Smith said:
Since May 2010, when the Coalition government came into power, Charles has also met:
- Chancellor George Osborne
- Education Secretary Michael Gove
- Business Secretary Vince Cable
- Work and Pensions Secretary Iain Duncan Smith
- Andrew Mitchell when he was International Development Secretary
- Jeremy Hunt, while he was Culture, Media and Sport Minister
A Clarence House spokesman said that, during the meetings between the Prince and ministers, Charles brings "important insights, perspectives and knowledge built over 40 years of experience in a range of areas aimed at transforming lives and building sustainable communities".