You may have missed it, but early last month, a very telling photograph appeared in the newspapers. Snapped on New Year's Day by a couple out for a walk on Coombe Hill in the Chilterns, it featured a party of eight – including David and Samantha Cameron, education secretary Michael Gove, film director Tim Burton, and the latter's extremely posh other half Helena Bonham Carter. According to subsequent gossip, the latter couple had been introduced to the Camerons by Bonham Carter's one-time Westminster school contemporary Nick Clegg. Others suggest that the two couples have been friends for years.

The group had reportedly stayed at Chequers, the prime minister's country retreat, on New Year's Eve – where the conversation doubtless turned to Bonham Carter's role in The King's Speech, the most accomplished example to date of our new appetite for tales of troubled bluebloods and intrigue on country estates. In its own way, then, this was an image of the New Britain as telling as Tony Blair's famous Downing Street encounter with Noel Gallagher: proof of a new blurring of Tory politics and popular culture that speaks volumes about our times.

Other examples abound. There is surely a deeply zeitgeisty aptness to the fact that Julian Fellowes, the creator of Downton Abbey, has recently become a working Tory peer. Though whispers about her own arrival in the upper house have died down, TV's aristo homebuyer and make-and-mend guru Kirstie Allsopp remains an equally fervent supporter of the Conservatives. And what about Gilbert & George, apparently enthusiastic Tories whose civil partnership and combination of tweedy tradition and metropolitan urbanity surely make them honorary Cameroons? "We admire Margaret Thatcher greatly," George said in 2009. "She did a lot for art. Socialism wants everyone to be equal. We want to be different."

Last year, Tracey Emin came good on pre-election talk about her pro-Tory leanings – sparked by her loud opposition to Labour's 50p tax rate – by claiming Britain now had "the best government we've ever had". On the campaign trail, David Cameron launched Tory plans for a new National Citizen Service with Michael Caine, and a proposed national "School stars" talent contest in the company of Take That's Gary Barlow. "There's no one more with-it than David," the latter assured an audience in Nantwich, Cheshire; by way of returning the compliment, Cameron hailed Take That as "Britain's best ever boyband".

For sure, there remain plenty of celebrity Tory endorsers who do not push quite the same A-list buttons, and instead suggest a time-honoured mixture of seaside summer seasons, golf jumpers and ITV: Cilla Black, Ronnie Corbett, William "Ken Barlow" Roache, Joan Collins, the ex-pop star and I'm A Celebrity contestant David Van Day. Pulses did not exactly quicken when they were joined by such names as Matt Willis, an erstwhile member of the teen-pop trio Busted, and Spandau Ballet's Tony Hadley.

Yet the main point is inarguable: there is a whiff of stardust around the Tories that would once have been unthinkable. It's easily forgotten now, but there were very serious rumours about Mark Ronson DJing at the 2009 Tory conference, and giving Cameron a public endorsement. Now, in a twist no one would have seen coming, Courtney Love recently attended a "Port and Policy" debate organised by Oxford University's Conservative Association, and was given the post of "non-executive officer for rock'n'roll". Photos of the accompanying revellers show Love – who is dating Kirstie Allsopp's art dealer brother, Henry – dutifully posing in front of a union flag with a mostly-male array of student Tories, who look about as non-rock'n'roll as you might imagine. What Kurt Cobain would have made of it all is anyone's guess.

Helena Bonham Carter and Tim Burton are apparently friends of the Camerons. Photograph: Samir Hussein/Getty Images

There is, then, something afoot: a waning of the old stigma that got in the way of "creatives" backing the Tories, and resulted in any who did facing loud ridicule. Consider the case of the synth-pop icon Gary Numan – these days a name it's perfectly OK to drop, with a dependable cult following. Back in the 1980s, his public statements of support for the Thatcher government made him a music press pariah, and played some role in his fall (as late as 2003, however, he was unrepentant: "Thatcher had a clear idea about everything and seemed to be massively pro-British against the rest of the world," he said). In 2010, by contrast, the other Gary's campaigning for the Tories caused no career damage whatsoever: it simply stood as an above-average photo opportunity, crashlanded on the evening news, and was promptly forgotten.

So what has changed? Cameron's diligent attempts to rebrand his party by affecting the role of the modern, bike-riding urban dad and paying endless tributes to his favourite rock bands have undoubtedly helped. The same applies to the feting of his supposedly switched-on wife.

Much more important, though, is the wider context. Whether austerity will bring a renewed ideological charge to the relationship between politics and culture is an interesting point: certainly, the famous names who have protested about arts cuts and library closures suggest that very familiar battle-lines are already reappearing. That said, we still largely live in the post-Blair age, in which the right-left divide is not nearly as entrenched as it once was, and people's political preferences count for much less. Whisper it, then – but after decades of ignominy, it might just be OK to be a pop-culture Conservative.

In any case, the arts are aligning themselves with the Tories in ways much more subtle and insidious than simple endorsements. Just as New Labour managed to slot itself into the wider moment known as Cool Britannia, so there are lines that can be drawn from musicians, actors, film-makers and novelists to people at the top of government. Here, the arriviste likes of Barlow are less important than a new elite who speak with the same accents as people at the top, and attest to a simple fact: the privately educated seem to be newly dominant, and a sharp change of tone and taste stretches from politics, to the arts, and beyond.

The demotic affectations – glottal stops, photo-ops in greasy spoon cafes, an affected love of football – that were obligatory 15 years ago have completely disappeared. Last year, there was a flurry of news coverage when the Word magazine reported that during one week in October, 60% of the acts in the UK charts came from privately educated backgrounds, although it subsequently printed a letter pointing out that its figure were erroneously exaggerated [see footnote]. When this story was revived last week in an item on the Today programme it brought a furious emailed response from one Jane Blount, better known as the mother of that renowned Harrow alumnus James Blunt.

Barely a day goes past, it seems, when you cannot pick up a newspaper and find the latest sensation in music, or film, or literature, expounding on an early life of dormitories, tuck shops and "prep". Take, for example, the actor Dominic West – AKA Jimmy McNulty in The Wire, and just cast in an ITV drama as the serial killer Fred West. He went to Eton, his wife is a former countess, he has a daughter from a relationship with a member of the Astor dynasty, and he is – but of course – a friend of the Camerons. He is also said to have once had a soft spot for the prime minister's wife. When asked, he has occasionally seemed uneasy about his background, though he has tended to end up sounding much the same rather questionable notes as the Old Etonians in government. "It probably helps that we now live in a meritocracy," he mused two years ago, "so we don't need to worry where people came from."

Earlier this month, the Daily Mail roundly ignored such sentiments, and captured the new mood in a list of "Britain's 50 most powerful posh people under 30": they included Florence Welch of Florence and the Machine, the rather irksome comedian Jack Whitehall, two members of the "nu-folk" sensations Mumford & Sons, and Sophie Winkleman, better known as Big Suze from Peep Show.

Accompanying the list was a piece by Dylan Jones, the long-standing editor of GQ, another supporter of the Tories, and the author of the in-his-own words book Cameron On Cameron. "Privately educated scions of the great and the good no longer feel that everyone is against them," he wrote.

"What is more, they are happy to proclaim their status and to exploit it. Look around you. So many fields of public life are now dominated by those with, at the very least, a private education, [and] in many cases wealth and in a few instances a title. In the arts, sport, television, fashion, music, nightlife and, of course, politics, it's positively Brideshead Revisited Revisited."

Or, if you prefer, Born To Rule Britannia.

• This article was amended on 3 February 2011. The original stated that Word magazine discovered that, in one week in October, 60% of the acts in the UK charts came from privately educated backgrounds. It failed to take into account that Word subsequently published a letter pointing out that this figure was erroneously exaggerated. This has been corrected.