First we have Prince Charles’s mystical musings on genetic modification, then his sister disagrees, then dad weighs in with a broadside contrasting GM with exotic grey squirrels, and finally his sister backtracks, trying to play peacemaker between warring familial egos, declaring the jury is still out on GM after all. What has poured across newspaper columns these past few days is an echo of conversations around dinner tables, bars and coffee machines. For once, the Windsors’ comments may be more informed than those of many of their subjects. The three are statistically rare in Britain for having some experience of farming on their estates. The Duke of Edinburgh took his responsibilities at the World Wildlife Fund seriously, as does the Princess Royal as head of Save the Children and the Prince of Wales has long had an interest in environmentalism.

But for all their qualifications to speak and their passionately held views, it does not look good to have the royal family airing their disagreements in public. It smacks too much of older emotional feuds being played out in proxy – Prince Philip has never had much time for his son’s “romanticism”, as he politely describes it. This kind of skirmishing deals another blow to a constitutional monarchy whose unique selling point for much of the last century was family unity.

It is hard to see now how the Firm can ensure this kind of public bust-up does not happen again. Monthly meetings over lunch with a list of controversial issues to divvy up? “Charles, you do endangered butterflies and architects, I’ll do Africa’s starving and child labour,” the Princess Royal might suggest – only for an unseemly squabble to ensue about whether GM is endangering the butterflies but could feed Africa’s children. And then there is the tricky question of who gets invited: does the Queen Mother have views on GM? And is Princess Margaret poised to tell us of its impact on Mustique?