With a full-blown slump but months away, the Queen is setting the trend for the nation, as she has in past times of trouble.

Her natural frugality certainly chimes with the times we’re living through. Early on in the credit crunch, the Queen was ahead of the curve when she cancelled her Diamond Wedding party at the Ritz last March.

Mary Riddell writes in the Telegraph that the Prime Minister, Gordon Brown, hopes the Queen will bring back the feelgood factor to the nation by demonstrating how to be cheerful in a depression. Stoicism through thick and thin has always been HM’s strong point. The PM has clearly noticed.

Gerald Warner, writing in his blog, makes an interesting point: “Gordon Brown wants the Queen and the royal family to lead the nation in hair-shirt frugality, to give an example to the rest of us in these poverty-stricken times. Which is strange, considering it is only three days since Gordon threw good money after bad by doubling the National Debt to £1 trillion [$1.5tr].”

The Prime Minister is, says Warner, hiding behind the Queen’s skirt.

Constitutional expert Peter Hennessey reinforces the point, “The Queen does not need Number 10 to make her into an effective focus for the country. She is such a remarkable figure, she naturally fulfils that function. The Queen has this great gift for adapting without going for fads or fashions. She does not need telling what is required to do. She just does it.”

However, Mary Riddell reports, “At Number 10, where the House of Windsor’s tactics are being followed with interest, Mr Brown is said to speak ‘in affectionate terms’ of his meetings with the Queen.”

The Queen has apparently ordered all senior members of the Royal Family only to be present at low-key occasions and to avoid glossy or glamorous events.

Prince William and Prince Harry have been asked to cleave to the military, while avoiding nightclubs and big, brassy charitable parties.

Royal women will be expected to recycle their outfits, something Princess Anne has been doing for decades. All in all, the Royals will set the style and tone for the hard times to come, with the Queen, as always, way out in front.

I confess to a deep sense of foreboding as I write these words. For we are now being fed a picture of just how much the Monarchy will change under the reign of the present Prince of Wales.

Prince Charles holding a Kendo stick in Japan

Monarchies need to adapt and change, of course, and when a new personality ascends the throne it may be the ideal moment to introduce difficult and systemic changes into the old institution.

These innovations may come sooner than we think. There is a whisper going around that the Queen may pass the mantle of Monarchy to her son and heir when he is 65 — a mere five years from now. Last week we heard her refer to his future Kingship in public for the first time.

As if to drive the point home, a steady stream of leaks and suggestions is being released by credible media figures.

The country has been informed that Charles will keep his promise to drop the “Defender of the Faith” subtitle, for the looser, and therefore less-Christian, “Defender of Faith”. Any old faith will do, it seems, as long as you believe in something.

The former Archbishop of Canterbury, George Carey, spoke out recently against “destructive changes” being made to the old constitution, which has proved its worth over time. He clearly senses a disestablishment of the Church of England.

Last week, a close friend of the Prince, Jonathan Dimbleby, suggested that Charles could become an “active” King, speaking out on issues close to his heart, like climate change, education, architecture and conservation. The Irish and German Presidents were singled out as examples he may follow. Although they are neutral politically, they do get involved in day-to-day discussions on policy matters.

Prince Charles already boycotts Chinese leaders because of their treatment of Tibet. He once called them “appalling old waxworks”. Imagine the political fury if he refuses to attend a State banquet for the President of one of the world’s most powerful trading nations, as he has in the past?

The difference between the Queen and the Presidents of Ireland and Germany is that they are elected by a franchise of the whole population. They have legitimacy for activism — and therefore unpopularity — within their constitution.

British Constitutional Monarchs are expected to follow the convention that they can speak out in private at the weekly meeting with the Prime Minister and warn of future consequences. Other than that, the role is purely ceremonial, except as a last resort longstop against tyranny.

If a King Charles were to take on a Prime Minister directly, he would be swiftly marginalized by crafty and practised political infighters. He wouldn’t stand a chance. His humiliation would be complete, especially under a Labour government.

The Monarchy will not last long under those circumstances. Everything the present Queen has built up as the “unifier of the nation” would be lost. Politicians would begin by destroying what is left of our constitutional checks and balances — as Blair and Brown have gradually done for the past 10 years.

The package of measures Charles’s team of helpers are placing in the media, combined with the almost certain crowning of Camilla, could result in a serious dip in popularity for the Monarchy.

Other countries, over which the Queen now reigns, may decide to dump the Crown as well, leading to a crisis for the new King that could be impossible to contain.

His friend the 14th Dalai Lama was prophesied to be the last leader of Tibet. He is now an exile outside his country.

Will Prince Charles be the last Monarch of the United Kingdom, itself under threat from Scottish nationalism?

There are dangerous shoals ahead for the Prince. Shoring up what he has got may be a better path to Kingship than challenging the people’s representatives. In the end, influence is a more durable form of governance than power itself.

With the Prince of Wales’s 60th birthday looming tomorrow, Friday, celebrations got off to an exuberant start last night with an evening of comedy at the New Wimbledon Theatre, London.

John Cleese, of Monty Python fame was the master of ceremonies for the evening together with former Fawlty Towers co-star Andrew Sachs, Manuel to his fans. The idea was to give Prince Charles a very special occasion in the presence of a host of comic superstars.

Meanwhile, over at the BBC, an excellent documentary cum interview with the Prince was broadcast last night. It was conducted by Robert Hardman of the Daily Mail and examined every aspect of Charles’s life and charity work. The range of subjects over which Charles presides with great aplomb and expertise must be mind-blowing to anyone who doesn’t keep up.

Tonight, a dinner, with an orchestral performance, will be given by the Queen in honour of her son and heir. Yesterday, she was heard to praise his public-spirited work for charity and even referred glancingly to his future role as King, which is not something she normally mentions in public.

In these depressive times, you would expect the famously frugal Monarch to cut costs even at such a banquet. And indeed the wines selected by the Queen to enhance the Balmoral salmon and venison dishes, are notable but not lavish.

Puligny Montrachet Les Olivier Leflaive, 2006 at £40 ($60) a bottle, will refresh the palette without exciting aficionados of fine wine. The red, Chateau Leoville-Barton St Julien, 1988, around £100 ($150), will be excellent after a few glasses of the white.

The dessert wine is a nice 1996 Sauternes, and a suitably expansive note to end on.

The absence of conductor Riccardo Muti owing, apparently, to a disagreement over the length of his proposed programme and perhaps his fee, will not dampen spirits at what should be a glittering event.

On Wednesday evening, Prince William attended a gala evening of music and food in London to mark the end of his year as Patron of the Lord Mayor’s Appeal.

The constantly solo Prince suggests that Kate Middleton has resumed her role as casual girlfriend rather than the “Girlfriend,” to which she had been promoted, according to recent reports, with the consent of the Queen.

The Grand Finale of the event was at St Paul’s Cathedral in celebration of the end of the appeal for 2008.

Money was raised throughout the year for Wellbeing of Women, which funds research into women’s health, and Orbis, which works to prevent blindness in developing countries.

David Lewis. the Lord Mayor of the square-mile financial district, who should not be confused with Boris Johnson, the publicly-elected Mayor of all London, said of the occasion:

“I have had such a wonderful and exciting year with tremendous support from many people and organisations in the City. I am delighted that many of our friends have joined us to celebrate the Grand Finale to my Lord Mayor’s appeal.”

William now steps down as the Appeal’s Patron.

Quite what this quiet period in Kate’s role signifies for the future is not yet crystal clear. My guess is that the high spot of the relationship has passed and an enduring friendship has replaced it.

The Prince will be fully occupied from January with an 18-month spell of intensive training as a helicopter pilot with the RAF’s Search and Rescue unit. The belief is that he will make the grade and go on to serve for up to six years in various remote spots around Britain, and possibly abroad.

Marriage, it seems, is the last thing on his mind.

As for Kate, she is rebuilding her life and expectations within the Middleton family business and, no doubt, will re-emerge into the London night scene as the fancy takes her.