Prince Charles' 'black spider' letters: What has Clarence House been fighting to protect?

Supreme Court judges did not read the letters

The 27 notes have been dubbed the “black spider” memos due to the Prince’s unique style of handwriting (Charles Fred Thornhill/Reuters)

The seven Supreme Court justices who handed down their judgement today were only deciding upon a point of law, so they did not have to read the 27 letters which both Clarence House and Government have fought so hard to keep secret.

One of the only people who knows what is in the so-called “black spider” memos – penned by Prince Charles to seven different Government departments over a seven-month period in 2004 and 2005 – is Dominic Grieve, the former Attorney General who vetoed their publication in 2012.

Justifying his decision not to release them at the time, he said that much of the correspondence reflected Prince Charles’s “most deeply held personal views and beliefs” and were “in many cases particularly frank”.

He continued: “They also contain remarks about public affairs which would in my view, if revealed, have had a material effect upon the willingness of the government to engage in correspondence with the Prince of Wales, and would potentially have undermined his position of political neutrality.”

The correspondence reflects Prince Charles’s 'most deeply held personal views and beliefs' (Arthur Edwards/Getty Images)

Prince Charles is known for his strong opinions on a range of topics, from the environment and farming to complementary medicine and architecture. Perhaps his most notorious intervention came in 1984, when he described plans for a new extension to the National Gallery as a “monstrous carbuncle on the face of a much-loved and elegant friend”. The project was later scrapped.

More recently, he wrote to Sheikh Hamad bin Khalifa Al-Thani, the emir of Qatar, urging his family to drop plans for a radical redevelopment of Chelsea Barracks in favour of a more traditional alternative. The plans were later shelved, leading to accusations that he had abused his “privileged position”.

The seven departments which received letters from Prince Charles in 2004 and 2005 were 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.

Mr Grieve said he believed they had been written “as part of the Prince of Wales’s preparation for becoming king”, and that the disclosure of their contents could damage his ability to perform his duties as monarch. “It is a matter of the highest importance within our constitutional framework that the monarch is a politically neutral figure able to engage in confidence with the government of the day, whatever its political colour,” he added.

Soon, the British public will be able to judge for themselves whether or not he was right.