Some bizarre pictures appeared in the Daily Mail this week, of William and Kate walking away from a helcopter on a London airfield. It turned out that the pictures had been taken over a month ago, apparently by plane spotters who had not realised they had photographed William and Kate (and Lupo) until they downloaded the pictures a few weeks later.

The palace issued a terse, off-the-record response to the Mail, telling the journalist that the helicopter was owned by a friend, that the trip was neither "chartered" nor '"paid for" and that the trip was simply a "gift" from a friend.

The chopper belongs to Shoreham-based Eastern Atlantic Helicopters, whose managing director Simon Oliphant-Hope is a friend of the couple. Mr Oliphant Hope, 49, said: "I know the couple and occasionally, when I am routing past North Wales, I give them a lift if it is convenient to all parties."

Nice friend, eh?

By sheer bad luck, the pictures emerged just days before it was officially annouced that the budget for renovating William and Kate's new ten-bedroom home in Kensington Palace had hit the £1 million mark, and that the Queen would be getting an increase in her budget from £31 to £36 million. The sovereign grant is used to pay for official duties, maintaining the royal palaces and paying staff.

To make maters worse, the disclosures of the vast sums of money being spent on the royals and their quarters came the very day after the British chancellor announced another round of savage spending cuts, which, among other things, are leading to closures of humble community projects and local swimming pools.

The only saving grace for the royals is that the British press are currently too excited about the birth of the royal baby, expected any day now, to start laying in to the royals for their extravagance (not that this stopped a news report of the Queen's "pay rise" on the Guardian attracting thousands of comments from outraged left-wingers).

But Graham Smith, the leader of the pressure group Republic, which campaigns gainst the monarchy, issued a statement saying, "As everyone else is seeing cuts to services and jobs it is unbelievable that our head of state will sit silently by as she is handed millions more in public money. We’ve had two years of royal celebrations that have cost the taxpayers millions—surely it’s time the Queen gave something back.”

“The Crown Estate is not—and never has been—the personal property of the royals. The Windsors have no more right to its revenue than I do. To claim that it should fund their lavish lifestyle is deceitful and dishonest.”

It is usually the older members of the royal family who are most frequently acused of extravagance, and Kate and William are understandably keen to prevent too many images of them hopping on and pff their mates helicopters surfacing in the press. (Much better were the pics of Wiliam getting on a train in Wales the other day for the trip to London).

Yet there is a definite tension between the common touch that William and Kate so effortlessly display, and the undoubted luxury of a royal lifestyle.

Since January 2012, William and Kate have been on foreign holidays no less than five times; to Mustique not once but twice, to the south of France (scene of the topless photos), to Courcheval skiing and then skiing again after attending a friend’s wedding in Switzerland.

The British papers, terrified of rattling the Leveson cage, have been strangely mute on the subject, and are reluctant to criticize Kate and William. But when you talk to ordinary people, although there is compassion for the fact that William and Kate have to live their life under the press microscope, there is also a growing sense of astonishment at the increasingly apparent extravagance of their lifestyles.

And "apparent" is the key word. The Queen, sensibly, spends all her holidays at Balmoral or Sandringham, where she can truly be assured of total privacy. 

Kate and William have played the part of a "normal couple" down to a T, but when you see them cheerfully sliding down the side of crisp, Swiss moutains, still tanned from a week on the beach in Mustique, it is hard not to think they are the one-percenter’s one-percenters.

The February Mustique trip played particularly badly in public perception. It’s not hard to see why. Just weeks before, the palace had been furiously spinning the story of Kate’s appalling morning sickness, that was so awful and debilitating she couldn’t possibly be expected to attend any planned events.

And yet she was OK for an eight-hour flight to the Carribbean followed by a short hop in a light aircraft? The childish sulk about being photographed on a public beach while the rest of the population shivered in a freezing late winter garnered little sympathy either.

William’s father, Prince Charles, has always been noted for his rather millionairey tastes, and with him the criticism is usually focused on the number of staff he employs—the harpist, the sketch artist, the valet who, it was once revealed, squeezes toothpaste onto his brush.

With William and Kate, however, the picture is more nuanced. They have very few staff; Kate is still determined not to have a nanny and famously recycles her high street clothes to cut down on the attire bill. (Yesterday she was wearing a chocolate brown coat last worn when she visited Action on Addiction in 2012.) But they do undeniably seem to spend a fortune on their private vacations.

The palace has let it be known that of the past five trips, two of them—he 2012 Mustique holiday and the ski trip to Courcheval—were paid for by the Middletons. But the idea that William and Kate paid for their other private vacations out of his £45,000 RAF salary is clearly wide of the mark. William has a fortune estimated to be in the region of £20m left to him by his late mother, and will in due course inherit the massive cash cow that is the Duchy of Cornwall, when Charles accedes.

Having been reportedly given a vast country home by the Queen, William is widely rumored to have personally lent the Middletons several million pounds to buy a new house last year, and the Middletons themselves, thanks to their astonishingly successful party-planning business - are hardly short of a few bob.

The continuing success of William and Kate in reinvigorating the once-moribund British monarchy relies on the public’s ability to identify with them. Kate is the girl next door, William is the guy anyone would be happy for their mother to meet. They ask their staff to call them by their first names.

But now and again the mask slips. And this week’s pictures of them hopping of a pal's helicopter, combined with the astonishing sums being spent on their massive London home, reminded the British people again of the uncomfortable truth that for all her mastery of the common touch, Kate and William are really much more like them.