The Islands have been mentioned in a hard-hitting Channel 4 documentary which accuses the Prince of Wales of meddling in political affairs.
Charles is said to be furious over claims made by the Dispatches programme that he uses secret lobbying to influence policy.
The show also raises serious questions about the management of the Duchy of Cornwall.
Researchers used the Freedom of Information Act to gain financial information about the Duchy’s dealings from the Treasury.
They claim to have found letters from the Duchy to an elderly couple on Bryher asking if they would surrender the lease on a cottage to alleviate the chronic local housing problem. In good faith, the couple agreed and a local family moved in for more than a year.
But after spending ?300,000 upgrading the property, the Duchy decided the only way to claw its investment back was to let the house to visitors.
The Little House now has a tariff of ?1750 in July and August. The other property let directly to visitors, The Guard House on St Mary’s, charges ?1850 per week in August.
The change of use of both buildings caused outrage on the Islands, particularly on Bryher which has a very limited local housing stock. Councillor Gordon Bilsborough has described the Duchy’s housing policy as ?immoral? and ‘blatant profiteering’.
Meanwhile, the show claims that Charles keeps a staff of more than 100 people, has the use of five houses (including Tamarisk on Scilly) and spent more ?1 million on travelling last year alone.
The Duchy says it receives only a minimal return from the Islands and points out that it effectively contributes a large financial subsidy, such as the investment of more than ?2 million to refurbish the off-Island quays for no direct financial return.
It also says it has built seven new local dwellings over the last four years.
But the show’s main criticism of the future King is that he abuses his position and interferes in government policy.
Lord Wedderburn QC, a life peer, said: “If nothing changes and he becomes King, there would be a most almighty fuss and controversy. The whole fabric of the constitutional Monarchy could be threatened.”
The Duchy responded that Charles “of all people” knew the duties of the Heir to the Throne were different from those of the Sovereign, and that his role would change when he became King.
All in all it hasn’t been a good week for the Prince or his green credentials. Camilla has been roundly condemned for having a pair of shoes flown 3000 miles to Kuwait and then failing to wear them.
Perhaps worse was Charles’s suggestion that the McDonald’s fast-food chain should be banned because of its unhealthy menu.
US TV channel CBS made short work of the idea, pointing out that, “a meat pie (known in the UK as a pasty) in the Prince’s own organic food line, contains more calories and saturated fat than a Big Mac.?
Maybe it’s time for HRH to think about putting a sock in it.