A Guardian journalist accused the Attorney General Dominic Grieve of failing to show "reasonable grounds" for blocking the release of letters sent by Prince Charles to government ministers.
The High Court today ruled that Grieve's use of a ministerial veto to stop the letters being published was unlawful but the Attorney General said he will "pursue an appeal."
The public has a right to know if the heir to the throne is advocating policy or promoting causes to government ministers.
We welcome today's appeal court judgment finding that it was wrong to block the release of the letters.
We hope the Attorney General will recognise he has reached the end of the legal road and that government departments will now publish the correspondence so that the public can judge for themselves.
More top news
Giraffes could disappear from the planet if current rates of extinction continue, it has been warned.
Foreign Secretary Boris Johnson has been filmed accusing British ally Saudi Arabia of "puppeteering" in the Middle East.
Psychotic illnesses such as schizophrenia may be linked to immune system disorders, research has found - opening up new treatments.