Prime Minister David Cameron and Prince Charles expressed dismay Thursday at a Supreme Court ruling that paves the way for publication of Charles' letters to government ministers.

A spokesman for Charles said "Clarence House is disappointed the principle of privacy has not been upheld."

The case involves letters Charles has written to seven government departments. They are believed to contain strong personal views.

Cameron said the government will now consider how to release the letters, which have been sought by the Guardian newspaper for roughly a decade.

The prime minister said the case was about "the principle that senior members of the royal family are able to express their views to government confidentially. I think most people would agree this is fair enough."

The timetable for the release of the letters is not yet clear. The government has long tried to block their release, but the Supreme Court upheld an earlier ruling backing their publication.

Critics have charged that Charles has become too involved in advocating positions. He is first in line for the throne, and is expected to remain politically neutral.

In the past he has expressed strong views on architecture, climate change, genetically modified foods, and other matters.