SECRET letters sent by the Prince of Wales to government ministers will finally be published today after a ruling by the UK’s highest court.

Charles’s correspondence with ministers – known as “black spider” memos – will be released after a long-running battle by Guardian newspaper journalist Rob Evans to see the documents following a freedom of information request.

The letters will be published with some redactions after the Upper Tribunal’s ruling that it “has accepted Mr Evans’s submission that what is described in the decision as ‘the open material’ is to be supplied to other parties without restriction on their ability to publish that material”.

The decision of the tribunal included a proviso the material could be published subject to any “provisional redactions” to protect personal data of people other than Charles.

Supreme Court judges finally approved the publication of the letters in March.

The Prince’s notes were sent to Government departments and written between September 2004 and March 2005.

They reflect, said previous attorney general Dominic Grieve, Charles’s “most deeply held personal views and beliefs’’.

The documents were due to be published at 3pm.