PM and spin king enjoy the delights of 'Poshstock'

(Getty Images)

The ninth annual Cornbury Festival took place this weekend on the picturesque, 4,000-acre Great Tew Estate in Oxfordshire, a little under seven miles from Chipping Norton.

Among the attractions were kids' yoga classes, morris dancing and Alison Moyet. The event is popular with such Tatler-bait as Jemima Khan and Tamara Beckwith Veroni.

But only those lucky enough to gain admittance to the VIP area had the opportunity to witness Saturday's star turn: David Cameron, making awkward small-talk with his former spin doctor, Andy Coulson.

Ted Heath used to be a fixture at Glyndebourne, John Major at Lords, but for the present Conservative Prime Minister, Cornbury – frequently referred to as "Poshstock" – is the biggest date of the social season. Cameron's encounter with Coulson was unplanned and he avoided a similar meeting with fellow Chipping Norton Settee, Rebekah Brooks, who also attended the festival.

But it's a social minefield that the CNS may have to navigate more than once this summer, due to the Cotswolds' high concentration of genteel music festivals. Until 2010, Cornbury was held a few miles away, on Lord and Lady Rotherwick's 6,500-acre Cornbury Estate. When its organiser, Hugh Phillimore, fell out with the Rotherwicks, he moved his festival to Great Tew. The original site is now home to the HMV-backed Wilderness Festival.

No less embarrassing than bumping into Coulson was Cameron's much-papped chat with Jeremy Clarkson and cheesemaker Alex James at last year's Harvest Festival, on James' farm in Kingham (just over the Burford Road from Charlbury). Harvest's organisers Big Wheel Promotions went into administration soon afterwards. In its place this coming September we have "Jamie Oliver presents The Big Feastival with Alex James".

Why so many summer festivals in the same neighbourhood? Is it the density of private estates, or the well-heeled demographic?

According to Phillimore, 52: "It's a collection of lunatics who all happen to be living close together."

The Cornbury Festival 2012 line-up included Jools Holland, Will Young, Macy Gray and Pixie Lott. For children, this year's organisers laid on "African Dance Workshops" and clay modelling.