Prince Charles, pictured today, has been told his letters to ministers must be released despite warnings it would infringe his 'freedom of expression' Prince Charles's 'lobbying' of ministers is set to continue unabated – even though more than two dozen private letters already written by him on issues of Government policy will be made public within weeks. Clarence House yesterday expressed its 'disappointment' that the Supreme Court ruled the Attorney General had acted unlawfully in using a veto to block publication of his so-called 'black spider' memos. But senior royal sources also insisted to the Mail that the future king had no regrets about acting as an 'advocate' for his people. One said the judgment was 'unlikely to impact' on Charles doing what sees as his public duty. Yesterday's ruling by the UK's highest court follows a nine-year legal battle between the Government and The Guardian newspaper, which used the Freedom of Information Act to apply for 27 letters written by the Prince to senior politicians to be released. The Prime Minister also said he was disappointed by the ruling. Charles has long been accused of bombarding ministers with memos in an attempt to influence policy on issues close to his heart such as the environment, farming, the countryside, GM crops and complementary medicine. During the period in question – September 2004 to April 2005 – he wrote to seven Government departments: Business, Innovation and Skills; Health; Children, Schools and Families; Environment, Food and Rural Affairs; Culture, Media and Sport; the Northern Ireland Office and the Cabinet Office. The correspondence – nicknamed black spider memos because of Charles's scrawling handwriting and use of underlining and exclamation marks – is said, according to previous Attorney General Dominic Grieve, to contain 'full and frank' expressions of his 'most deeply held personal views'. The newspaper was initially successful in its application. In 2012, however, the Attorney General employed a rarely-used ministerial veto to block publication under Section 53 of the FOI Act. He said the public could interpret the letters sent to ministers in the last Labour government as showing Charles 'disagreeing with government policy'. This would be 'seriously damaging to his role as future monarch because, if he forfeits his position of political neutrality… he cannot easily recover it when he is king'. That veto was challenged by The Guardian in the Supreme Court which ruled, by a majority of five to two, that the government did not have a right to overrule a decision taken by the courts. Charles and Camilla today spent today riding in a rickshaw at Clarence House to promote a race across Madhya Pradesh, India later this year . Views: An August 2000 letter from Lord Irvine, Tony Blair's mentor and later the Lord Chancellor, heavily annotated by Prince Charles in his 'black spider' handwriting . The seven Supreme Court judges made their ruling on two legal points. One was whether Dominic Grieve, the Attorney General in 2012, was right to issue a Section 53 certificate under the Freedom of Information Act, effectively blocking publication of the letters. The other question was whether an obscure EU directive – the 2003 Environmental Information Regulations – meant that any specific environmental information contained in Charles’s letters must be published. Lord Neuberger, the court president, said the Court of Appeal had already rejected Mr Grieve’s arguments that Charles’s views must be kept private. He said that it was not lawful for ‘a member of the executive to overrule a judicial decision simply because he disagrees with it’. Four other judges agreed that the letters should be published but Lord Hughes and Lord Wilson disagreed. Lord Wilson said the Appeal Court judges had ignored the constitutional principle of parliamentary sovereignty. Six of the judges said that environmental matters in Charles’s letters should be made public under the EU directive. Discussions are under way as to how to co-ordinate the release of the 27 letters. This may not happen for several weeks but they are likely to prove embarrassing to the Prince. They cover issues such as the Armed Forces, the plight of foot and mouth-hit farmers and other rural concerns. They are probably the only letters to be released because the law has been changed to make correspondence by senior members of the Royal Family exempt from FOI requests. Mr Cameron echoed Clarence House's views yesterday, saying: 'This is a disappointing judgment and we will now consider how to release these letters. This is about the principle that senior members of the Royal Family are able to express their views to government confidentially.' A spokesman for the Prince said: 'Clarence House is disappointed the principle of privacy has not been upheld.' David Cameron said the ruling was 'disappointing' and argued that senior Royals should be able to communicate with ministers 'confidentially' But senior royal sources also insisted that Charles and his team were quite 'sanguine' about the decision. 'This has come down to quite a narrow legal principle and was not about the content of the letters,' one said. The source rejected descriptions of the future king as a meddler, insisting he was an 'advocate' simply trying to shine a light on issues raised with him by members of the general public. Asked whether the ruling would stop the Prince writing to ministers, the source said: 'This is a small loophole in the law that the government have very quickly closed. I can't imagine it [the decision to publish] would impact on the Prince of Wales as he undertakes his public duties and service.' Letter lover: Prince Charles is said to have sent 1,000 letters a year at peak periods in his life . A defiant Prince Charles has always maintained he has the right  to express his forthright views to ministers even after he becomes King. At peak periods, his passionate words have poured out at the rate of 1,000 letters a year to ministers and other public figures. As the furore over his 'black spider' letters peaked in 2012, the heir to throne was said to be unrepentant about the row furore sparked by the Government's decision to stop 27 'particularly frank' letters written to ministers in the last Labour government to be revealed. Courtiers told the Mail that it is the prince's 'right and absolute duty' to correspond with politicians over issues that affect his country and future subjects. And sources close to the prince made clear that Charles will continue to air his opinions, even during his private meetings with the Prime Minister after he accedes to the throne. 'The Prince of Wales absolutely sees it as his duty to make his views known to ministers,' they said. 'He is a man of passionate belief and will always strive to make his views clear.' As a self-confessed 'interfering busybody', Charles has become renowned for expressing his strong views on a huge variety of issues ranging from youth opportunity to architecture and the environment. His prolific missives are known as 'black spider memos' because of his scrawled handwriting. Explaining his willingness to get involved in issues and causes he said himself: 'The trouble is, I always feel that unless I rush about doing things and trying to help furiously, I will not (and the monarchy will not) be seen to be relevant and I will be considered a mere playboy.'
Attorney General made a final attempt to block release of Charles' letters . High Court wanted release but Government appealed to Supreme Court . Known as 'black spider' memos because of royal's scrawled handwriting . Prince wrote to at least seven departments about variety of subjects .