That noise you can hear coming from St James's Palace is a huge sigh of relief.

For the British government has stepped in to block the imminent release of a series of letters written by Charles to government ministers, known as the ‘black spider memos’, due to the Prince’s spiky handwriting and use of black ink.

It is rumoured that many of the letters, which tend to be on pet subjects such as architecture and alternative healthcare, begin with the words, "It really is appalling..."

The Guardian newspaper had sought the release of the letters under freedom of information legislation, but now the letters have been blocked on appeal after the attorney general, issued a veto that puts an absolute block on the publication of 27 letters between the prince and ministers.

Bizarrely, the reason given for the ban on publication of the ‘particularly frank’ letters is that they may lead the British public to question Charles’s impartiality when he becomes King.

Of course, this is exactly the Guardian's point.

The attorney general said: "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…In summary, my decision is based on my view that the correspondence was undertaken as part of the Prince of Wales's preparation for becoming king. The Prince of Wales engaged in this correspondence with ministers with the expectation that it would be confidential. Disclosure of the correspondence could damage the Prince of Wales's ability to perform his duties when he becomes king.

"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."

The Guardian has vowed to appeal to the High Court to get the letters released.