But that was not all. The advisers - who included Commander Richard Aylard, his former private secretary, Richard Sandbrook, founder of Friends of the Earth, and a new recruit, Dr Simon Lyster, head of the wildlife trusts - then turned their attention to the future. Each guest gave a five-minute presentation suggesting ways in which Charles could continue to promote the environment. Last week's intervention may have been the Prince's most vocal foray into politics, but it is not going to be his last. On the issues he feels strongly about, friends say he intends to say what he thinks, however uncomfortable that might be for the Government. The decline in rural communities, the erosion of traditional country life and poverty among farmers - all difficult areas for Tony Blair - are likely to feature heavily in future speeches or articles.
Both Downing Street and St James's Palace insist that reports of a "stand- up row" between the Prime Minister and the Prince about genetically modified food were "overblown". But the two men had discussed the subject, not just at a meeting in St James's Palace five weeks ago but also at a Highgrove lunch in September; according to Royal advisers, the Prince got the distinct impression that Cherie Blair, who was also there, was far more worried about the new technology than her husband.
Charles's decision to restate his concerns just days after Mr Blair had dismissed media "hysteria" over the subject was certainly embarrassing for the Government. There was panic among its strategists on Tuesday morning because Jack Cunningham, who is supposed to speak for the Government on this issue, was away from his desk, relaxing at home. Michael Meacher, the environment minister who is more sceptical about the benefits of GM crops, was sent on to the Today programme instead. He was privately delighted to be given such a free rein - "it gave him a bit of space to take a more cautious line", a close aide said. Today, on GMTV, he will say that the Government is "anxious" to talk to the Prince about his concerns.
The timing of the Prince's article, shortly after the Government's high- profile attempt to allay public fears, was a coincidence. He had been asked by the Daily Mail to write a piece more than two months previously and agreed the publication date two weeks in advance. And St James's Palace insists that the Prince was only reiterating views he has held for years.
The trouble is that a lot of the things which interest the Prince have also moved to the centre of the political stage; however apolitical it might have seemed two years ago, GM food is now definitely a Government matter. It is also something which has divided the political parties, with the Tories urging greater caution on the Government. Some Labour insiders suspect that the Prince might have been influenced by his conservative, if not Conservative, circle of friends and advisers. The first draft of the Daily Mail article was put together by Elizabeth Buchanan, his assistant private secretary, a staunch Conservative who used to work as an adviser to Margaret Thatcher. She is on secondment to the Prince from Bell Pottinger, the PR company owned by the Tory peer Lord (Tim) Bell.
But the Prince's office insists that he is not getting into party politics. "A lot of the things the Prince of Wales has said over the years have suddenly become popular. Years ago he was the potty Prince, talking to his plants; now everyone is interested in the environment," one adviser said. "He's not going to stop talking about things just because they become politicised." Patrick Holden, director of the Soil Association and an unofficial adviser to Charles, believes the Prince just has an "uncanny knack" of spotting issues. "He sees the significance of things before even the experts do and raises questions. That is an entirely responsible use of his power and influence."
It is no coincidence that the Prince went public about something which has become of increasingly wide public concern in recent months. A concerted effort is being made to humanise Charles, to make the man and woman in the street understand him. This week's trip to a Versace fashion show and photocalls such as the one in the Sheffield benefits office, based on a scene from The Full Monty, are all part of an attempt to make him more down to earth. When he goes to Scotland, his advisers want him to visit drug rehabilitation centres dressed in a suit rather than being pictured strolling around Balmoral in a kilt. Just as the hereditary members of the House of Lords have chosen to challenge Mr Blair on issues on which they can be "peers and people" against the Government, so Charles's circle wants to align their man with the concerns of his future subjects. "The target of the Daily Mail article was Middle England," one adviser said. And Charles hit it: by Wednesday lunchtime the Palace had received 800 e-mails from people supporting his stance. For once, it began to appear that Charles could perhaps be the "People's Prince" in the way that his wife was once the "People's Princess".
This outspokenness is going to continue. The Prince had originally planned to use the Daily Mail article to launch a new international commission to investigate the GM industry's claim that their crops could help to feed the world's poor. The idea was to bring together a team of experts, under the chairmanship of Sir Crispin Tickell, a Government environment adviser, to look into one of the apparently most attractive aspects of biotechnology. The commission was to have worked closely with the International Institute for Environment and Development which has done pioneering work on how traditional, organic farming methods could greatly increase production in the Third World. It was originally going to be launched in February but this was postponed "to let the dust settle" during the outcry that month over the findings by Dr Arpad Pusztai that GM potatoes seemed to have damaged laboratory rats.
Two weeks ago, Prince Charles cancelled the idea, following the publication of several other reports on the same subject - but the plan shows the extent to which he is determined to pursue his interests.
The Prince's advisers insist that the commission was not abandoned because of pressure from Downing Street. Certainly, Charles is not afraid to take on the Government if he thinks this is necessary. Top of the agenda next is the countryside, again another tricky issue for Tony Blair. And again it is of concern to the public. And if the Government thinks this issue is of short-term concern to the royal family, it should think again. Prince William has just been elected Secretary of the Agriculture Society at Eton.
JONATHAN DIMBLEBY, PAGE 26; JOAN SMITH, PAGE 27